Income Taxes (Details 3) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Income Tax Disclosure [Abstract]
Beginning balance	$ 1,375	$ 816	$ 470
Increases in unrecognized tax benefits - prior year positions	0	0	0
Increases in unrecognized tax benefits - current year positions	459	559	346
Ending balance	$ 1,834	$ 1,375	$ 816