Employee Benefit Plans (Expected Benefit Payments) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011
Defined Benefit Plan Disclosure [Line Items]
2012	$ 6,822
2013	7,044
2014	7,347
2015	7,603
2016	7,948
2017-2021	41,068
Qualified Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
2012	46,428
2013	49,444
2014	52,795
2015	56,468
2016	60,498
2017-2021	366,223
Non-Qualified Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
2012	5,051
2013	4,963
2014	4,951
2015	4,925
2016	4,947
2017-2021	$ 24,684