Employee Benefit Plans Schedule of Defined Benefit Plan Activity (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Amounts recognized in the consolidated balance sheets:
Prepaid pension costs	$ 12,870	$ 10,047
Non-current employee benefits	(45,860)	(45,982)
Pension Plans [Member]
Change in benefit obligation:
Benefit obligation at January 1	(151,008)	(148,968)
Service cost	(1,275)	(1,422)	(1,360)
Interest cost	(6,513)	(7,481)	(8,131)
Benefits paid	12,813	11,448
Expenses paid	308	430
Actuarial (gain) loss	(8,041)	(5,015)
Benefit obligation at December 31	(153,716)	(151,008)	(148,968)
Change in plan assets:
Fair value of plan assets at January 1	122,012	132,993
Actual return on plan assets	15,656	537
Expenses paid	(308)	(430)
Contributions	3,513	360
Benefits paid	(12,813)	(11,448)
Fair value of plan assets at December 31	128,060	122,012	132,993
Funded status at December 31	(25,656)	(28,996)
Amounts recognized in the consolidated balance sheets:
Prepaid pension costs	12,870	10,046
Other accrued liabilities	(2,161)	(2,057)
Non-current employee benefits	(36,365)	(36,985)
Net amounts recognized	(25,656)	(28,996)
Other Postretirement Benefits [Member]
Change in benefit obligation:
Benefit obligation at January 1	(9,635)	(9,850)
Service cost	(14)	(13)	(13)
Interest cost	(465)	(500)	(521)
Benefits paid	512	534
Expenses paid	0	0
Actuarial (gain) loss	(556)	194
Benefit obligation at December 31	(10,158)	(9,635)	(9,850)
Change in plan assets:
Fair value of plan assets at January 1	0	0
Actual return on plan assets	0	0
Expenses paid	0	0
Contributions	512	534
Benefits paid	(512)	(534)
Fair value of plan assets at December 31	0	0	0
Funded status at December 31	(10,158)	(9,635)
Amounts recognized in the consolidated balance sheets:
Prepaid pension costs	0	0
Other accrued liabilities	(663)	(656)
Non-current employee benefits	(9,495)	(8,979)
Net amounts recognized	$ (10,158)	$ (9,635)