Stockholders' Equity (Details) (USD $) In Millions, except Share data, unless otherwise specified	0 Months Ended		1 Months Ended	12 Months Ended
	Nov. 22, 2011	Oct. 27, 2010	Feb. 28, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Stockholders' Equity
Shares authorized under share repurchase program		$ 25	$ 10
Shares of common stock purchased	6,601,313			1,300,000	5,300,000	0
Value of shares of common stock purchased	$ 8.3			$ 1.2	$ 10.6
Purchase price per share (in dollars per share)	$ 1.25
Additional common shares purchased pursuant to the option to increase the size of the offering by 2% of the outstanding shares of common stock	601,313
Percentage of increase in the size of the offering to purchase additional common shares	2.00%
Shares purchased as a percentage of shares outstanding immediately prior to the consummation of the tender offer	5.17%