Income Taxes Reconciliation of the beginning and ending amount of gross unrecognized tax benefits (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Beginning balance of gross unrecognized tax benefits	$ 1,070	$ 1,351	$ 2,189
Reductions in gross unrecognizzed tax benefits	0	0	(912)
Additions based on tax provisions related to the current year	0	95	0
Reductions for the tax provisions of prior years	(164)	(11)	342
Reductions for settlement and payments	(318)	(118)	(70)
Reductions due to statute expiration	0	(247)	(198)
Ending balance of gross unrecognized tax benefits	$ 588	$ 1,070	$ 1,351