Other Income, net (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Other Income (Expense), net [Abstract]
Other income, net	$ 1,000	$ 1,806	$ 3,582	$ 5,704
Interest Income [Member]
Other Income (Expense), net [Abstract]
Other income, net	909	906	2,709	3,599
Other Nonoperating Income [Member]
Other Income (Expense), net [Abstract]
Other income, net	441	619	1,807	1,972
Insurance Policy (Expense) Income [Member]
Other Income (Expense), net [Abstract]
Other income, net	(350)	283	(934)	142
Other Nonoperating Expense [Member]
Other Income (Expense), net [Abstract]
Other income, net	$ 0	$ (2)	$ 0	$ (9)