Income Taxes (Details 3) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Reconciliation of the beginning and ending gross amount of unrecognized tax benefits
Balance at beginning of year	$ 24,122	$ 27,778
Additions based on tax positions related to the current year	240	78
Additions for tax positions of prior years	2,186	4,119
Reductions for tax positions of prior years - Settlement	(2,547)	(6,486)
Reductions for tax positions of prior years - Statute of limitations	(802)	(1,367)
Balance at end of year	$ 23,199	$ 24,122