Income Taxes (Details 3) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Changes in the company's unrecognized tax benefits
Balance at the beginning of the period	$ 3,551,000	$ 3,273,000
Decreases related to settlements	(184,000)
Decreases related to expiration of statute of limitations	(133,000)
Gross increases related to current year's tax positions	285,000	278,000
Balance at the end of the period	3,519,000	3,551,000	3,273,000
Total amount of unrecognized tax benefits that, if recognized, would impact the effective tax rate	2,400,000
Anticipated decrease in total unrecognized tax benefits in the next twelve months	2,300,000
Interest expenses recognized as a component of income tax expense	400,000	200,000	300,000
Interest and penalties accrued	$ 700,000	$ 400,000