Amount of net tax benefit (deficiency) from vesting of share-based payment awards.

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- Definition

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

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Amount of tax benefit for recognition of expense of award under share-based payment arrangement.

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- Definition

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.

+ References

No definition available.

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- Definition

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

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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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Stock-Based Compensation and Other Employee Benefit Plans (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended			12 Months Ended
	Dec. 31, 2019	Mar. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Stock-Based Compensation and Other Employee Benefit Plans [Line Items]
Stock-based compensation plans, number of shares available for future grant	3,865,000			3,865,000
Non-cash stock-based compensation expense				$ 16.4	$ 13.5	$ 15.7
Stock-based compensation, income tax benefits				7.9	4.9	11.2
Stock-based compensation, vested awards, net income tax benefits	$ 1.6	$ 2.3	$ 1.3	$ 3.9	$ 1.6	$ 5.4
2013 Incentive Plan [Member] \| Restricted Shares [Member]
Stock-Based Compensation and Other Employee Benefit Plans [Line Items]
Stock-based compensation plans, number of shares authorized	7,391,000			7,391,000
ESPPs [Member] \| Employee Stock Purchase Plans [Member]
Stock-Based Compensation and Other Employee Benefit Plans [Line Items]
Stock-based compensation plans, number of shares authorized	3,000,000			3,000,000