Annual report pursuant to Section 13 and 15(d)

Retirement Plan (Details)

v2.4.0.6
Retirement Plan (Details) (USD $)
In Thousands, unless otherwise specified
12 Months Ended
Dec. 31, 2011
Dec. 31, 2010
Dec. 31, 2009
Retirement Plan [Abstract]      
Pension expense $ 5,146 $ 4,044 $ 3,499