Other Income, Net (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Other Income (Expense), Net [Abstract]
Other income, net	$ 476	$ 98	$ 1,265
Interest Income [Member]
Other Income (Expense), Net [Abstract]
Other income, net	736	324	1,190
Other Nonoperating Income [Member]
Other Income (Expense), Net [Abstract]
Other income, net	129	67	459
Insurance Policy Expense [Member]
Other Income (Expense), Net [Abstract]
Other income, net	(389)	(283)	(384)
Other Nonoperating Expense [Member]
Other Income (Expense), Net [Abstract]
Other income, net	$ 0	$ (10)	$ 0