|
Short-Term And Long-Term Investments And Restricted Deposits (Tables)
|
12 Months Ended |
|
Dec. 31, 2011
|
| Short-Term And Long-Term Investments And Restricted Deposits [Abstract] |
|
| Short-Term And Long-Term Investments And Restricted Deposits By Investment Type |
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
|
December 31, 2011 |
|
|
December 31, 2010 |
|
| |
|
Amortized
Cost |
|
|
Gross
Unrealized
Gains |
|
|
Gross
Unrealized
Losses |
|
|
Fair Value |
|
|
Amortized
Cost |
|
|
Gross
Unrealized
Gains |
|
|
Gross
Unrealized
Losses |
|
|
Fair Value |
|
|
U.S. Treasury securities and obligations of U.S. government corporations and agencies
|
|
$ |
29,014 |
|
|
$ |
638 |
|
|
$ |
(13 |
) |
|
$ |
29,639 |
|
|
$ |
28,665 |
|
|
$ |
510 |
|
|
$ |
(140 |
) |
|
$ |
29,035 |
|
|
Corporate securities
|
|
|
186,018 |
|
|
|
3,762 |
|
|
|
(751 |
) |
|
|
189,029 |
|
|
|
197,577 |
|
|
|
3,124 |
|
|
|
(586 |
) |
|
|
200,115 |
|
|
Restricted certificates of deposit
|
|
|
5,890 |
|
|
|
— |
|
|
|
— |
|
|
|
5,890 |
|
|
|
6,814 |
|
|
|
— |
|
|
|
— |
|
|
|
6,814 |
|
|
Restricted cash equivalents
|
|
|
13,775 |
|
|
|
— |
|
|
|
— |
|
|
|
13,775 |
|
|
|
8,814 |
|
|
|
— |
|
|
|
— |
|
|
|
8,814 |
|
|
Municipal securities:
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
General obligation
|
|
|
126,806 |
|
|
|
2,828 |
|
|
|
(26 |
) |
|
|
129,608 |
|
|
|
109,866 |
|
|
|
3,601 |
|
|
|
(6 |
) |
|
|
113,461 |
|
|
Pre-refunded
|
|
|
33,247 |
|
|
|
465 |
|
|
|
— |
|
|
|
33,712 |
|
|
|
32,442 |
|
|
|
756 |
|
|
|
— |
|
|
|
33,198 |
|
|
Revenue
|
|
|
118,507 |
|
|
|
2,387 |
|
|
|
(34 |
) |
|
|
120,860 |
|
|
|
100,198 |
|
|
|
2,781 |
|
|
|
(15 |
) |
|
|
102,964 |
|
|
Variable rate demand notes
|
|
|
64,658 |
|
|
|
— |
|
|
|
— |
|
|
|
64,658 |
|
|
|
106,540 |
|
|
|
— |
|
|
|
— |
|
|
|
106,540 |
|
|
Asset backed securities
|
|
|
51,779 |
|
|
|
430 |
|
|
|
(17 |
) |
|
|
52,192 |
|
|
|
17,391 |
|
|
|
243 |
|
|
|
(43 |
) |
|
|
17,591 |
|
|
Cost and equity method investments
|
|
|
9,395 |
|
|
|
— |
|
|
|
— |
|
|
|
9,395 |
|
|
|
7,060 |
|
|
|
— |
|
|
|
— |
|
|
|
7,060 |
|
|
Life insurance contracts
|
|
|
14,699 |
|
|
|
— |
|
|
|
— |
|
|
|
14,699 |
|
|
|
14,391 |
|
|
|
— |
|
|
|
— |
|
|
|
14,391 |
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Total
|
|
$ |
653,788 |
|
|
$ |
10,510 |
|
|
$ |
(841 |
) |
|
$ |
663,457 |
|
|
$ |
629,758 |
|
|
$ |
11,015 |
|
|
$ |
(790 |
) |
|
$ |
639,983 |
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Schedule Of Available-For-Sale Investments In A Continuous Unrealized Loss Position |
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
|
December 31, 2011 |
|
|
December 31, 2010 |
|
| |
|
Less Than 12 Months |
|
|
12 Months or More |
|
|
Less Than 12 Months |
|
|
12 Months or More |
|
| |
|
Unrealized
Losses |
|
|
Fair
Value |
|
|
Unrealized
Losses |
|
|
Fair
Value |
|
|
Unrealized
Losses |
|
|
Fair
Value |
|
|
Unrealized
Losses |
|
|
Fair
Value |
|
|
U.S. Treasury securities and obligations of U.S. government corporations and agencies
|
|
$ |
(13 |
) |
|
$ |
2,184 |
|
|
$ |
— |
|
|
$ |
— |
|
|
$ |
(140 |
) |
|
$ |
9,246 |
|
|
$ |
— |
|
|
$ |
— |
|
|
Corporate securities
|
|
|
(751 |
) |
|
|
23,040 |
|
|
|
— |
|
|
|
— |
|
|
|
(586 |
) |
|
|
40,341 |
|
|
|
— |
|
|
|
— |
|
|
Municipal securities:
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
General obligation
|
|
|
(26 |
) |
|
|
3,710 |
|
|
|
— |
|
|
|
— |
|
|
|
(6 |
) |
|
|
1,131 |
|
|
|
— |
|
|
|
— |
|
|
Revenue
|
|
|
(34 |
) |
|
|
12,597 |
|
|
|
— |
|
|
|
— |
|
|
|
(15 |
) |
|
|
2,419 |
|
|
|
— |
|
|
|
— |
|
|
Asset backed securities
|
|
|
(17 |
) |
|
|
20,417 |
|
|
|
— |
|
|
|
— |
|
|
|
(43 |
) |
|
|
5,276 |
|
|
|
— |
|
|
|
— |
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Total
|
|
$ |
(841 |
) |
|
$ |
61,948 |
|
|
$ |
— |
|
|
$ |
— |
|
|
$ |
(790 |
) |
|
$ |
58,413 |
|
|
$ |
— |
|
|
$ |
— |
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Contractual Maturities Of Short-Term And Long-Term Investments And Restricted Deposits |
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
|
December 31, 2011 |
|
|
December 31, 2010 |
|
| |
|
Investments |
|
|
Restricted Deposits |
|
|
Investments |
|
|
Restricted Deposits |
|
| |
|
Amortized
Cost |
|
|
Fair
Value |
|
|
Amortized
Cost |
|
|
Fair
Value |
|
|
Amortized
Cost |
|
|
Fair
Value |
|
|
Amortized
Cost |
|
|
Fair
Value |
|
|
One year or less
|
|
$ |
129,232 |
|
|
$ |
130,499 |
|
|
$ |
19,666 |
|
|
$ |
19,666 |
|
|
$ |
21,141 |
|
|
$ |
21,346 |
|
|
$ |
17,387 |
|
|
$ |
17,392 |
|
|
One year through five years
|
|
|
406,140 |
|
|
|
413,953 |
|
|
|
7,085 |
|
|
|
7,152 |
|
|
|
464,270 |
|
|
|
474,255 |
|
|
|
5,368 |
|
|
|
5,366 |
|
|
Five years through ten years
|
|
|
34,945 |
|
|
|
34,961 |
|
|
|
— |
|
|
|
— |
|
|
|
39,732 |
|
|
|
39,731 |
|
|
|
— |
|
|
|
— |
|
|
Greater than ten years
|
|
|
56,720 |
|
|
|
57,226 |
|
|
|
— |
|
|
|
— |
|
|
|
81,860 |
|
|
|
81,893 |
|
|
|
— |
|
|
|
— |
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Total
|
|
$ |
627,037 |
|
|
$ |
636,639 |
|
|
$ |
26,751 |
|
|
$ |
26,818 |
|
|
$ |
607,003 |
|
|
$ |
617,225 |
|
|
$ |
22,755 |
|
|
$ |
22,758 |
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Gross Recorded Realized Gains And Losses On Investments |
| |
|
|
|
|
|
|
|
|
|
|
|
|
| |
|
2011 |
|
|
2010 |
|
|
2009 |
|
|
Gross realized gains
|
|
$ |
314 |
|
|
$ |
6,036 |
|
|
$ |
1,252 |
|
|
Gross realized losses
|
|
|
(27 |
) |
|
|
(270 |
) |
|
|
(1,111 |
) |
|
Impairment of investment
|
|
|
— |
|
|
|
(5,531 |
) |
|
|
— |
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
Net realized gains (losses)
|
|
$ |
287 |
|
|
$ |
235 |
|
|
$ |
141 |
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|