Goodwill and Intangible Assets - Finite-lived Intangible Assets Roll Forward (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Finite-lived Intangible Assets, Gross [Roll Forward]
Intangible assets, January 1	$ 6,900	$ 6,900
Additions	702	0
Total intangible assets, end of year	7,602	6,900
Accumulated Amortization [Roll Forward]
Accumulated amortization	(6,900)	(6,895)
Current year amortization	(75)	(5)
Total accumulated amortization	(6,975)	(6,900)
Net intangible assets, end of year	$ 627	$ 0