Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Statement of Financial Position [Abstract]
Common stock, par value (usd per share)	$ 0.01	$ 0.01
Authorized shares—200,000,000	200,000,000us-gaap_CommonStockSharesAuthorized	200,000,000us-gaap_CommonStockSharesAuthorized
Issued shares—69,550,073 and 69,131,892	69,550,073us-gaap_CommonStockSharesIssued	69,131,892us-gaap_CommonStockSharesIssued
Outstanding shares—68,991,902 and 69,131,892	68,991,902us-gaap_CommonStockSharesOutstanding	69,131,892us-gaap_CommonStockSharesOutstanding

Face amount or stated value per share of common stock.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

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Number of shares of common stock outstanding. Common stock represent the ownership interest in a corporation.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef

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-Number 210

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Reference 2: http://www.xbrl.org/2003/role/presentationRef

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Reference 3: http://www.xbrl.org/2003/role/presentationRef

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Reference 4: http://www.xbrl.org/2003/role/presentationRef

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