Earnings Per Share (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Dilutive Securities Adjustments [Line Items]
Net Income (Loss) Attributable to Parent	$ 130,386us-gaap_NetIncomeLoss	$ 109,296us-gaap_NetIncomeLoss	$ 41,818us-gaap_NetIncomeLoss
Undistributed Earnings (Loss) Allocated to Participating Securities, Basic	372	681	212
Net Income (Loss) Available to Common Stockholders, Basic	130,014	108,615	41,606
Net Income (Loss) Available to Common Stockholders, Basic [Abstract]
Reallocation of Net Income to Participating Securities	6	93	212
Net Income (Loss) Available to Common Stockholders, Diluted	131,059	118,148	57,921
Weighted Average Number of Shares Outstanding, Basic	230,710	187,032	160,105
Incremental Weighted Average Shares Attributable to Dilutive Effect [Abstract]
Weighted Average Number of Shares Outstanding, Diluted	236,731	235,330	243,004
Earnings Per Share, Basic and Diluted [Abstract]
Earnings Per Share, Basic	$ 0.56us-gaap_EarningsPerShareBasic	$ 0.58us-gaap_EarningsPerShareBasic	$ 0.26us-gaap_EarningsPerShareBasic
Earnings Per Share, Diluted	$ 0.55us-gaap_EarningsPerShareDiluted	$ 0.50us-gaap_EarningsPerShareDiluted	$ 0.24us-gaap_EarningsPerShareDiluted
Stock Options and Restricted Share Awards [Member]
Incremental Weighted Average Shares Attributable to Dilutive Effect [Abstract]
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements	712	21	241
Convertible Notes Due 2014 [Member]
Net Income (Loss) Available to Common Stockholders, Basic [Abstract]
Interest on Convertible Debt, Net of Tax	$ 1,039	$ 9,440	$ 16,103
Incremental Weighted Average Shares Attributable to Dilutive Effect [Abstract]
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements	5,309	48,277	82,658
Earnings Per Share, Basic and Diluted [Abstract]
Interest rate of convertible subordinated notes	6.00%

Adjustment for dilutive securities on net income, net income reallocated to participating securities

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Contractual interest rate for funds borrowed, under the debt agreement.

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The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of share based payment arrangements using the treasury stock method.

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Net income after adjustments for dividends on preferred stock (declared in the period) and/or cumulative preferred stock (accumulated for the period).

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Net Income or Loss Available to Common Stockholders plus adjustments resulting from the assumption that dilutive convertible securities were converted, options or warrants were exercised, or that other shares were issued upon the satisfaction of certain conditions.

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