Employee Benefit Plans Plans with Benefit Obligations in Excess of Assets Table (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Pension Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Benefit obligation	$ (37,660)	$ (33,470)
Plan assets	25,770	19,140
Benefit obligation in excess of plan assets	(11,890)	(14,330)
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Benefit obligation	(970)	(1,040)
Plan assets	0	0
Benefit obligation in excess of plan assets	$ (970)	$ (1,040)