Quarterly report pursuant to Section 13 or 15(d)

Benefit Plans (Details)

v2.4.0.6
Benefit Plans (Details) (USD $)
In Thousands, unless otherwise specified
3 Months Ended
Mar. 31, 2013
Dec. 31, 2012
Mar. 31, 2013
Pension Benefits [Member]
Mar. 31, 2012
Pension Benefits [Member]
Mar. 31, 2013
Post Retirement Benefits [Member]
Mar. 31, 2012
Post Retirement Benefits [Member]
Components of net periodic benefit expense [Abstract]            
Service cost     $ 7,134 $ 6,217 $ 0 $ 0
Interest cost     7,307 7,304 216 338
Expected return on plan assets     (12,091) (11,433) 0 0
Amortization of transition asset     0 (1) 0 0
Amortization of prior service cost     (1,442) (1,442) (338) (338)
Amortization of gains (losses)     9,784 6,739 (150) (83)
Settlements     1,500 1,750 0 0
Benefit cost     12,192 9,134 (272) (83)
Change in Benefit Obligation [Roll Forward]            
Service cost     7,134 6,217 0 0
Interest cost     7,307 7,304 216 338
Change in Fair Value of Plan Assets [Abstract]            
Defined Benefit Plan, Fair Value of Plan Assets, Beginning Balance 649,609 633,617        
Defined Benefit Plan, Fair Value of Plan Assets, Ending Balance $ 649,609 $ 633,617