Subsequent Events (Details) (USD $) In Millions, except Share data, unless otherwise specified			0 Months Ended	9 Months Ended		0 Months Ended
	Sep. 30, 2012	Dec. 31, 2011	Oct. 03, 2012 Issuance of Equity [Member] Subsequent Event [Member]	Sep. 30, 2012 Common Stock [Member]	Sep. 30, 2012 Convertible Preferred Stock [Member]	Oct. 03, 2012 IPO [Member] Common Stock [Member] Issuance of Equity [Member] Subsequent Event [Member]	Oct. 03, 2012 IPO [Member] Convertible Preferred Stock [Member] Issuance of Equity [Member] Subsequent Event [Member]	Oct. 03, 2012 IPO Overallotment [Member] Common Stock [Member] Issuance of Equity [Member] Subsequent Event [Member]
Subsequent Event [Line Items]
Shares Sold in Initial Public Offering, Including Existing Shares						8,711,250
Shares sold in initial public offering, including existing shares, price per share						$ 12.00
Shares issued during period				724,458		7,836,250		1,136,250
Shares Sold by Existing Stockholders During Initial Public Offering						875,000
Proceeds from Issuance Initial Public Offering			$ 87.5
Payments of Stock Issuance Costs			$ (2.5)
Conversion of stock, shares converted							17,597,258
Common Stock, Shares Authorized	299,900,000	299,900,000	1,000,000,000
Preferred Stock, Shares Authorized			20,000,000		176,400,000