Income Taxes (Details 4) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Reconciliation of the unrecognized tax benefits
Balance at beginning of year	$ 3,647	$ 3,329	$ 2,924
Additions for tax positions of prior years		366	277
Additions for tax positions of current year			128
Reductions for tax positions of prior years	(3,598)	(48)
Balance at end of year	$ 49	$ 3,647	$ 3,329