Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Statement of Financial Position [Abstract]
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, authorized shares	50,000,000us-gaap_PreferredStockSharesAuthorized	50,000,000us-gaap_PreferredStockSharesAuthorized
Preferred stock, issued shares	0us-gaap_PreferredStockSharesIssued	0us-gaap_PreferredStockSharesIssued
Preferred stock, outstanding shares	0us-gaap_PreferredStockSharesOutstanding	0us-gaap_PreferredStockSharesOutstanding
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, authorized shares	150,000,000us-gaap_CommonStockSharesAuthorized	150,000,000us-gaap_CommonStockSharesAuthorized
Common stock, issued shares	98,828,000us-gaap_CommonStockSharesIssued	95,924,000us-gaap_CommonStockSharesIssued
Common stock, outstanding shares	98,828,000us-gaap_CommonStockSharesOutstanding	95,924,000us-gaap_CommonStockSharesOutstanding

Face amount or stated value per share of common stock.

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