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Amount of cost not yet recognized for nonvested award under share-based payment arrangement.

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Weighted-average period over which cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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Amount of cost to be recognized for nonvested award under share-based payment arrangement. Excludes share and unit options.

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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 over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

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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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Number of shares authorized for issuance under share-based payment arrangement.

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Percentage of vesting of award under share-based payment arrangement.

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Amount of stock repurchase plan authorized.

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Amount remaining of a stock repurchase plan authorized.

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Number of shares that have been repurchased during the period and have not been retired and are not held in treasury. Some state laws may govern the circumstances under which an entity may acquire its own stock and prescribe the accounting treatment therefore. This element is used when state law does not recognize treasury stock.

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Equity impact of the value of stock that has been repurchased during the period and has not been retired and is not held in treasury. Some state laws may mandate the circumstances under which an entity may acquire its own stock and prescribe the accounting treatment therefore. This element is used when state law does not recognize treasury stock.

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

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Stockholders' Equity (Narrative) (Details) - USD ($)	3 Months Ended
Stockholders' Equity (Narrative) (Details) - USD ($)	Mar. 31, 2020	Dec. 31, 2019	Sep. 04, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, par value (dollars per share)	$ 0.01	$ 0.01
Unrecognized compensation costs related to unvested awards	$ 18,300,000	$ 9,500,000
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation costs recognition period (years)	1 year
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation costs recognition period (years)	4 years
2013 Long Term Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized (in shares)	4,800,000
Common Stock \| 2017 Stock Repurchase Program
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock repurchase program, authorized amount			$ 200,000,000.0
Common stock, par value (dollars per share)			$ 0.01
Stock repurchase program, amount available for repurchase	$ 143,300,000
Common Stock \| 2019 Stock Repurchase Program
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate purchases (in shares)	1,200,000
Average price (in dollars per share)	$ 19.47
Aggregate purchases	$ 23,300,000
Time-based Stock Awards \| Long Term Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (shares)	294,725
Vesting period	4 years
RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (shares)	303,000
RSUs \| Long Term Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (shares)	351,730
Performance period	3 years
RSUs \| Long Term Incentive Plan \| End of Performance Period
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting rights (percent)	75.00%
RSUs \| Long Term Incentive Plan \| 1 Year Post Performance Period
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting rights (percent)	25.00%
Preferred OP Unit Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation costs recognition period (years)	4 years
Unvested unit awards	$ 22,100,000