Goodwill and Intangible Assets - Finite-lived Intangible Assets Roll Forward (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Finite-lived Intangible Assets, Gross [Roll Forward]
Intangible assets, January 1	$ 7,602	$ 6,900
Additions	0	0
Total intangible assets, end of period	7,602	6,900
Accumulated Amortization [Roll Forward]
Accumulated amortization	(6,975)	(6,900)
Current year amortization	(124)
Total accumulated amortization	(7,099)	(6,900)
Net intangible assets, end of period	$ 503	$ 0