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The cash outflow to reacquire common stock during the period.

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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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No definition available.

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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 authorized to be repurchased by an entity's Board of Directors under a stock repurchase plan.

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No definition available.

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Total cost of shares repurchased divided by the total number of shares repurchased.

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Cost basis for treasury stock acquired for purposes other than retirement.

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Number of shares that have been repurchased during the period and are being held in treasury.

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Stockholders' Equity - Incentive and Other (Details) - USD ($) $ / shares in Units, $ in Thousands, shares in Millions	12 Months Ended			144 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2018	May 31, 2017	May 31, 2012	Mar. 29, 2007
Share Repurchase Program
Number of shares of outstanding common stock authorized to be acquired under a stock repurchase program	8.8			8.8			1.0
Share repurchase (in shares)				8.2
Average price (in dollars per share)	$ 48.13			$ 16.24
Share repurchase	$ 28,533	$ 9,007	$ 13,088
Repurchased carrying basis	$ 28,500			$ 28,500
Maximum
Share Repurchase Program
Share repurchase (in shares)	0.6
2012 Equity Incentive Plan
Stockholders' Equity
Number of shares authorized and reserved for issuance						5.1
Number of shares available for issuance	2.9			2.9
2017 Omnibus Incentive Plan
Stockholders' Equity
Number of shares authorized and reserved for issuance					2.9
Number of shares available for issuance	2.6			2.6