Redemption of Series B Convertible Participating Preferred Stock (Details) (Series B preferred stock, USD $) In Millions, except Share data, unless otherwise specified	1 Months Ended
	Mar. 31, 2012
Series B preferred stock
Series B Preferred Stock
Outstanding shares redeemed by entity (in shares)	49,044
Value of outstanding shares redeemed by entity	$ 49.5
Cash dividend accrued prior redemption date	0.5
Unamortized stock issuance costs	$ 0.4