Common Stock Offering (Details) (USD $)	0 Months Ended	12 Months Ended
	May 01, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	May 01, 2013
Equity [Abstract]
Issuance of common stock in secondary public offering, net of offering costs (shares)	5,462,500
Sale of Stock, Price Per Share					$ 18.00
Underwriting Fees and Commissions, Per Share					$ 1.08
Net Proceeds from Stock Offering		$ 0	$ 92,034,000	$ 0
Payments of Stock Issuance Costs			$ 400,000