This represents the number of awards converted during the period by the entity

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The increments at which shares are awarded under the plan depending on achievement of performance goals.

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Represents the exercise price per share expressed as a percentage of fair market value of the common stock on the grant date.

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Number of annual performance periods over which performance targets are measured for determining potential compensation under the performance share awards.

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Represents the number of shares of common stock counted against the maximum shares available for grant for each share awarded under the plan.

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Percentage of award which can potentially be earned over the award period of share-based compensation awards.

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Estimated period over which an employee is required to provide service in exchange for the equity-based payment award, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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The maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested).

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The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

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The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

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The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan.

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Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares.

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For presentations that combine terminations, the number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan or that expired.

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Weighted average price of options that were either forfeited or expired.

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Net number of share options (or share units) granted during the period.

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The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

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Amount by which the current fair value of the underlying stock exceeds the exercise price of options outstanding.

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Number of options outstanding, including both vested and non-vested options.

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

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An excess of the fair value of the modified award over the fair value of the award immediately before the modification.

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Weighted average price at which option holders acquired shares when converting their stock options into shares.

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Weighted average per share amount at which grantees can acquire shares of common stock by exercise of options.

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The floor of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.

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The ceiling of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.

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Period from grant date that an equity-based award expires, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Amount of difference between fair value of the underlying shares reserved for issuance and exercise price of vested portions of options outstanding and currently exercisable.

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Weighted average remaining contractual term for vested portions of options outstanding and currently exercisable or convertible, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Weighted average remaining contractual term for option awards outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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

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Stock-Based Compensation - Stock-Based Compensation Plans (Details) $ / shares in Units, $ in Thousands					12 Months Ended
	Feb. 09, 2016 item shares	Jun. 12, 2014 shares	Jun. 09, 2011 shares	Jun. 01, 2003 shares	Dec. 31, 2016 USD ($) item $ / shares shares	Dec. 31, 2015 USD ($) $ / shares shares	Dec. 31, 2014 USD ($)	Jun. 11, 2014 shares	Jun. 08, 2011 shares
Maximum
Performance shares
Vesting period					4 years
Employee Stock Option and Stock Appreciation Rights
Stock-based compensation
Number of awards converted \| item					2
Incremental compensation cost recorded due to conversion \| $					$ 0
Employee stock options
Stock-based compensation
Exercise price of options granted, low end of range (in dollars per share) \| $ / shares					$ 6.76
Exercise price of options granted, high end of range (in dollars per share) \| $ / shares					$ 18.61
Number of Option Shares
Outstanding at the beginning of the period (in shares)					6,381,576
Granted (in shares)					1,573,651
Exercised (in shares)					(1,526,226)
Canceled (in shares)					(102,408)
Outstanding at the end of the period (in shares)					6,326,593	6,381,576
Weighted-Average Exercise Price
Outstanding at the beginning of the period (in dollars per share) \| $ / shares					$ 9.97
Granted (in dollars per share) \| $ / shares					12.92
Exercised (in dollars per share) \| $ / shares					7.77
Canceled (in dollars per share) \| $ / shares					13.76
Outstanding at the end of the period (in dollars per share) \| $ / shares					$ 11.17	$ 9.97
Additional disclosures
Weighted-Average Remaining Contractual Term					3 years 11 months 5 days
Aggregate Intrinsic Value (in dollars) \| $					$ 16,988,875
Weighted-average grant-date fair value of options granted (in dollars per share) \| $ / shares					$ 3.97	$ 4.85
Aggregate intrinsic value of stock options exercised (in dollars) \| $					$ 10,300	$ 19,500	$ 8,200
Number of Option Shares					3,110,050
Weighted-Average Exercise Price (in dollars per share) \| $ / shares					$ 9.34
Weighted-average remaining contractual term					2 years 4 months 13 days
Aggregate intrinsic value (in dollars) \| $					$ 13,900
Employee stock options \| Minimum
Stock-based compensation
Contractual lives of options granted					7 years
Employee stock options \| Maximum
Stock-based compensation
Contractual lives of options granted					10 years
Stock appreciation rights (SARs)
Performance shares
Vesting period					4 years
Restricted Stock
Performance shares
Awarded (in shares)					113,766
2003 Plan \| Maximum
Stock-based compensation
Number of shares of common stock available for awards				12,000,000
2003 Plan \| Incentive stock options \| Minimum
Stock-based compensation
Exercise price per share as a percentage of the fair market value of the Common Stock				100.00%
2003 Plan \| Nonqualified stock options \| Minimum
Stock-based compensation
Exercise price per share as a percentage of the fair market value of the Common Stock				85.00%
2008 Plan
Stock-based compensation
Number of shares of common stock available for awards		16,350,000	9,250,000					9,250,000	2,350,000
Options available for future grants (in shares)					3,856,137
2008 Plan \| Employee stock options
Stock-based compensation
Number of shares of common stock counted against the maximum shares available for grant for each share awarded under the plan		1
2008 Plan \| Stock appreciation rights (SARs)
Stock-based compensation
Number of shares of common stock counted against the maximum shares available for grant for each share awarded under the plan		1
2008 Plan \| Restricted stock and other full value stock awards
Stock-based compensation
Number of shares of common stock counted against the maximum shares available for grant for each share awarded under the plan			2.44
Performance Share Program \| Performance Shares
Performance shares
Awarded (in shares)	189,085
Number of annual performance periods \| item	3
Service period	3 years
Increment at which shares are awarded (as a percent)	33.30%
Vesting period	3 years
Performance Share Program \| Performance Shares \| Minimum
Performance shares
Percentage of award which can potentially be earned	0.00%
Performance Share Program \| Performance Shares \| Maximum
Performance shares
Percentage of award which can potentially be earned	150.00%