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Cash based compensation award, expenses

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Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Line Items]

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Period Of Service From Grant Date Stock Options Awarded Not Subject To Forfeiture

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Provisional compensation cash award approved for future grant by compensation committee, units

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Provisional Compensation Cash Award Approved for Future Grant by Compensation Committee, Value

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Share Based Compensation Arrangement By Share Based Payment Award Aggregate Fair Value

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Share Based Compensation Arrangement By Share Based Payment Award Award Vesting Date

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Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Option Nonvested Intrinsic Value

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Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Grants In Period Fair Value

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- Definition

Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Value

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Ultimate Award Value Multiples of Original Value of Units, Maximum

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Ultimate Award Value Multiples of Original Value of Units, Minimum

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Amount of noncash expense for award of restricted stock or unit under share-based payment arrangement.

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-Name Accounting Standards Codification
-Topic 230
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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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Fair value of share-based awards for which the grantee gained the right by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash.

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Date the equity-based award expires, in CCYY-MM-DD format.

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- Definition

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

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

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Description of terms of award under share-based payment arrangement.

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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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Restricted Stock, Performance Share and Cash Awards - Additional Information (Detail)				3 Months Ended				12 Months Ended
	Mar. 14, 2019 USD ($) shares	Mar. 15, 2018 USD ($) shares	Mar. 16, 2017 USD ($) shares	Mar. 31, 2019 shares	Mar. 31, 2018 shares	Mar. 31, 2017 shares	Mar. 31, 2016 shares	Dec. 31, 2019 USD ($) Times shares	Dec. 31, 2018 USD ($) shares	Dec. 31, 2017 USD ($) shares	Mar. 17, 2016 USD ($)	Mar. 11, 2015 USD ($) shares
Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Line Items]
Share-based compensation, shares outstanding \| shares								7,900,000	8,800,000	9,500,000
Shares granted in the period \| shares								414,700	439,100	476,350
Performance awards period, years								0 years
Long Term Incentive Plan [Member]
Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Line Items]
Share-based compensation, shares outstanding, Value								$ 4,000,000.0
Share-based compensation, shares outstanding \| shares								2,800,000
Shares granted in the period \| shares								2,800,000
Restricted Stock Units (RSUs) [Member]
Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Line Items]
Shares granted in the period \| shares				399,900	420,200	477,500		414,700	439,100	476,350
Fair value of grants in period								$ 31,800,000	$ 28,700,000	$ 26,800,000
Share based payment award vesting date								Mar. 14, 2024	Mar. 15, 2023	Mar. 19, 2022
Period of service from grant date stock options awarded not subject to forfeiture								2 years	2 years	2 years
Restricted stock or unit expense								$ 29,800,000	$ 27,200,000	$ 19,600,000
Unvested Restricted Stock [Member]
Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Line Items]
Total intrinsic value								215,100,000	140,800,000
Equity awards with an aggregate fair value								2,100,000	23,600,000
Performance Shares [Member]
Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Line Items]
Equity awards with an aggregate fair value								$ 5,700,000	3,700,000	$ 3,300,000
Shares authorized \| shares	73,600	78,200	86,250
Performance unit awards approved, Fair value	$ 5,800,000	$ 5,300,000	$ 4,900,000
Performance awards period, years								0 years
Vesting period, years								2 years
2019 Provisional Cash Awards [Member]
Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Line Items]
Performance awards expiration date								Jan. 01, 2022
Cash-based compensation awards, expenses								$ 8,900,000
2018 Provisional Cash Awards [Member]
Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Line Items]
Performance awards expiration date								Jan. 01, 2021
2017 Performance Share Awards [Member]
Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Line Items]
Provisional awards, terms								The 2019, 2018 and 2017 awards are subject to a three-year performance period that begins on January 1, 2019, 2018 and 2017, respectively, and vest on the three-year anniversary of the date of grant (March 14, 2022, March 15, 2021 and March 16, 2020)
Performance awards expiration date								Jan. 01, 2020
2017 Provisional Cash Awards [Member]
Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Line Items]
Cash-based compensation awards, expenses								$ 10,300,000	8,700,000
2016 Provisional Cash Awards [Member]
Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Line Items]
Performance awards expiration date						Jan. 01, 2019
Provisional compensation cash award approved for future grant by compensation committee, units \| shares								(341,000)		(199,000)
Cash-based compensation awards, expenses								$ 22,400,000	$ 11,700,000	$ 10,600,000
2015 Provisional Cash Awards [Member]
Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Line Items]
Performance awards expiration date							Jan. 01, 2018
Provisional compensation cash award approved for future grant by compensation committee, units \| shares									(269,000)
Cash-based compensation awards, expenses									$ 15,800,000	9,300,000
2014 Provisional Cash Awards [Member]
Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Line Items]
Cash-based compensation awards, expenses										$ 9,300,000
Officer and Key Employees [Member] \| Cash Awards [Member]
Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Line Items]
Provisional awards, terms								The ultimate award value will be equal to the trailing twelve-month price of our common stock on December 31, 2021, multiplied by the number of units subject to the award, but limited to between 0.5 and 1.5 times the original value of the units determined as of the grant date.
Vesting period, years								3 years
Provisional compensation cash awards approved for future grant by compensation committee, value	$ 16,500,000	$ 15,000,000.0	$ 14,300,000
Provisional compensation cash award approved for future grant by compensation committee, units \| shares	(206,800)	(219,000)	(255,000)	201,000	242,000			190,000
Ultimate award value, multiples of original value of the units, minimum \| Times								0.5
Ultimate award value, multiples of original value of the units, maximum \| Times								1.5
Officer and Key Employees [Member] \| 2016 Provisional Cash Awards [Member]
Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Line Items]
Provisional compensation cash awards approved for future grant by compensation committee, value											$ 17,400,000
Provisional compensation cash award approved for future grant by compensation committee, units \| shares						385,000
Officer and Key Employees [Member] \| 2015 Provisional Cash Awards [Member]
Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Line Items]
Provisional compensation cash awards approved for future grant by compensation committee, value												$ 14,600,000
Provisional compensation cash award approved for future grant by compensation committee, units \| shares							294,000					315,000
Executive Officer [Member] \| Minimum [Member] \| Restricted Stock Units (RSUs) [Member]
Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Line Items]
Minimum age of employee with not subject to award forfeiture on condition compliance					55 years			55 years	55 years	55 years