v2.4.0.8
Employee Benefit Plans (Consolidated Net Periodic Benefit Costs) (Details) (USD $)
In Thousands, unless otherwise specified
12 Months Ended
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2011
Pension Benefits [Member]
     
Components of net periodic pension and postretirement benefit expense:      
Service cost $ 13,901 $ 12,222 $ 9,628
Interest cost 5,368 4,862 4,343
Expected return on plan assets (6,228) (5,066) (4,357)
Amortization of prior service cost (credit) 307 307 307
Amortization of net actuarial loss 4,334 3,605 1,424
Settlement 0 0 70
Net periodic expense (credit) 17,682 15,930 11,415
Other Postretirement Benefits [Member]
     
Components of net periodic pension and postretirement benefit expense:      
Service cost 288 396 430
Interest cost 412 821 999
Expected return on plan assets 0 0 0
Amortization of prior service cost (credit) (3,712) (1,971) (851)
Amortization of net actuarial loss 1,035 1,021 167
Settlement 0 0 0
Net periodic expense (credit) $ (1,977) $ 267 $ 745