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Share-Based Compensation - Narrative (Details) - USD ($)			12 Months Ended
	May 15, 2012	Feb. 17, 2000	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	May 17, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee stock options granted in period (in shares)			0	0	0
Share-based compensation expense			$ 67,700,000	$ 79,400,000	$ 78,300,000
Amended And Restated Stock Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for issuance under the plan (in shares)	33,000,000.0					27,900,000
Common stock reserved and available for grant (in shares)						87,000,000.0
Aggregate of common stock available for grant (in shares)			16,500,000
Time Based Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized share-based compensation expense on non-vested restricted stock units			$ 74,500,000
Compensation expense recognized on restricted stock units			$ 52,500,000
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Recognition period for compensation expense (in years)			1 year 7 months 6 days
Restricted Stock | Director
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity awards granted in period (in shares)			100,000
Weighted average grant date fair value (In dollars per share)			$ 18.19
Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate of common stock available for grant (in shares)			3,000,000.0			28,500,000
Share-based compensation expense			$ 8,100,000
Maximum employee subscription rate for the ESPP (as a percent)		10.00%
Discount rate from market value paid by participants for shares under the plan (as a percent)		85.00%
Maximum annual amount of purchases per employee under the plan		$ 25,000
Shares authorized for purchase per employee per quarter (in shares)		500
Maximum fair value of shares employee may purchase in a quarter		$ 6,250
Shares issued pursuant to the employee stock purchase plan (in shares)			1,800,000	1,700,000	1,500,000
Employee Stock Purchase Plan | Director
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense			$ 1,500,000
Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Pre-vesting forfeitures (as a percent)			5.00%	5.00%	5.00%
Equity awards granted in period (in shares)			6,500,000
Compensation expense recognized on restricted stock units			$ 58,100,000
Weighted average grant date fair value (In dollars per share)			$ 19.50
Restricted Stock Units | Officers And Employees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity awards granted in period (in shares)			2,700,000
Service Based Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized share-based compensation expense on non-vested restricted stock units			$ 69,700,000
Service Based Restricted Stock Units | Amended And Restated Stock Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period (in years)	3 years
Performance And Market Based Restricted Stock Units | Amended And Restated Stock Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period (in years)	2 years
Performance Based Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized share-based compensation expense on non-vested restricted stock units			800,000
Market Based Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized share-based compensation expense on non-vested restricted stock units			$ 4,000,000.0

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

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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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The weighted average fair value at grant date for nonvested equity-based awards issued 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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