Other Income, Net (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Other Income (Expense), Net [Abstract]
Other income, net	$ 9,255	$ 31,143	$ 9,771
Interest Income [Member]
Other Income (Expense), Net [Abstract]
Other income, net	10,639	11,023	14,928
COLI Settlement [Member]
Other Income (Expense), Net [Abstract]
Other income, net	0	25,000	0
Other Nonoperating Income [Member]
Other Income (Expense), Net [Abstract]
Other income, net	3,722	1,689	3,650
Life Insurance Policy Expense [Member]
Other Income (Expense), Net [Abstract]
Other income, net	(4,785)	(6,529)	(8,646)
Other Nonoperating Expense [Member]
Other Income (Expense), Net [Abstract]
Other income, net	$ (321)	$ (40)	$ (161)