Net Loss Per Share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Earnings Per Share [Abstract]
Net loss	$ (80,196)us-gaap_NetIncomeLoss	$ (92,178)us-gaap_NetIncomeLoss
Denominator:
Average number of common shares outstanding	74,336,000	62,601,000
Basic and diluted net loss per share (in usd per share)	$ (1.08)us-gaap_EarningsPerShareBasicAndDiluted	$ (1.47)us-gaap_EarningsPerShareBasicAndDiluted
Effect of dilutive securities (in shares)	0	0
Anti-dilutive securities excluded from earnings per share calculation (in shares)	2,135,196	1,012,919
Share-based awards exercised or released
Stock options exercised (in shares)	0	9,641
Restricted stock units vested (in shares)	95,621	35,703
Total (in shares)	95,621	45,344

Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

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The amount of net income or loss for the period per each share in instances when basic and diluted earnings per share are the same amount and reported as a single line item on the face of the financial statements. Basic earnings per share is the amount of net income or loss for the period per each share of common stock or unit outstanding during the reporting period. Diluted earnings per share includes the amount of net income or 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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The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period.

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Number of share options (or share units) exercised during the current period.

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The sum of dilutive potential common shares or units used in the calculation of the diluted per-share or per-unit computation.

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Average number of shares or units issued and outstanding that are used in calculating basic and diluted earnings per share (EPS).

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Represents the number of share options and equity-based payment instruments, excluding stock (or unit) options, exercised and vested during the reporting period.

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