Consolidated Balance Sheets (Parenthetical) (Unaudited) (USD $)	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014
Statement of Financial Position [Abstract]
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001	$ 0.001
Common stock, authorized (in shares)	100,000,000us-gaap_CommonStockSharesAuthorized	100,000,000us-gaap_CommonStockSharesAuthorized	100,000,000us-gaap_CommonStockSharesAuthorized
Common stock, shares issued (in shares)	43,650,023us-gaap_CommonStockSharesIssued	43,511,093us-gaap_CommonStockSharesIssued	45,123,118us-gaap_CommonStockSharesIssued
Common stock, outstanding (in shares)	43,650,023us-gaap_CommonStockSharesOutstanding	43,511,093us-gaap_CommonStockSharesOutstanding	45,123,118us-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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-Name Accounting Standards Codification

-Topic 210

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-Section S99

-Paragraph 1

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-Publisher SEC

-Name Regulation S-X (SX)

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-Section 02

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The maximum number of common shares permitted to be issued by an entity's charter and bylaws.

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Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury.

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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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.3-04)

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

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-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

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-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.29)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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

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