Short-term and Long-term Investments, Restricted Deposits (Narrative) (Details) |
6 Months Ended |
|---|---|
|
Jun. 30, 2017
position
| |
| Schedule Of Investments And Restricted Deposits By Type [Line Items] | |
| Positions from which gross unrealized losses were generated | 1,375 |
| Total unrealized investment positions | 3,096 |
| Commercial mortgage-backed securities | |
| Schedule Of Investments And Restricted Deposits By Type [Line Items] | |
| Investments recorded at fair value that carry rating of AA Plus, weighted average (in years) | 3 years 10 months 24 days |
| Rated Securities | External Credit Rating, Investment Grade | |
| Schedule Of Investments And Restricted Deposits By Type [Line Items] | |
| Percentage of investments in rated securities carry an investment grade rating by S&P and Moody's | 94.00% |
| X | ||||||||||
- Definition Investments Recorded At Fair Value That Carry Rating Of A A Plus, Weighted Average, Duration No definition available.
|
| X | ||||||||||
- Definition Positions from which gross unrealized losses were generated No definition available.
|
| X | ||||||||||
- Definition Total Unrealized Investment Positions No definition available.
|
| X | ||||||||||
- Definition For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available.
|
| X | ||||||||||
- Details
|
| X | ||||||||||
- Details
|
| X | ||||||||||
- Details
|