Condensed Consolidated Statements of Equity - USD ($) $ in Millions		Total		Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit/Retained Earnings [Member]	AOCI Attributable to Parent [Member]	Treasury Stock [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance (in shares)				153,200,000				3,900,000
Cumulative effect of new accounting principle | Accounting Standards Update 2018-02 [Member]						$ (1.0)	$ 1.0
Beginning balance, adjusted		$ 1,786.5			$ 1,585.8	380.1	1.3	$ (180.7)
Beginning balance at Dec. 31, 2018		1,786.5			1,585.8	381.1	0.3	$ (180.7)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance (in shares)				153,100,000				3,400,000
Grant of restricted shares of common stock (in shares)								(800,000)
Grant of restricted shares of common stock					(37.3)			$ 37.3
Forfeitures of restricted shares of common stock					1.0			(1.0)
Tax withholding payments for restricted share vesting (in shares)				100,000
Tax withholding payments for restricted share vesting		$ (12.2)			(12.2)
Vesting of restricted shares granted from treasury stock					4.6			$ (4.6)
Vesting of restricted shares granted from treasury (in shares)								100,000
Stock Repurchased During Period, Shares		200,000						200,000
Stock Repurchased During Period, Value		$ (11.9)						$ (11.9)
Equity-based compensation expense		25.4			25.4
Net earnings		58.6				58.6
Equity-based compensation expense of unconsolidated affiliates		0.6				0.6
Foreign currency translation adjustment	[1]	0.0
Unrealized gains on interest rate swaps, net		(19.0)					(19.0)
Unrealized loss on investments in unconsolidated affiliates		(2.4)	[2]				(2.4)
Ending balance at Jun. 30, 2019		1,825.6			1,567.3	439.3	(20.1)	$ (160.9)
Ending balance (in shares) at Jun. 30, 2019				153,100,000				3,400,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance (in shares)				153,100,000				3,200,000
Beginning balance at Mar. 31, 2019		1,807.8			1,554.6	406.1	(5.8)	$ (147.1)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance (in shares)				153,100,000				3,400,000
Grant of restricted shares of common stock (in shares)								0
Grant of restricted shares of common stock					(0.1)			$ 0.1
Forfeitures of restricted shares of common stock					1.0			(1.0)
Tax withholding payments for restricted share vesting (in shares)				0
Tax withholding payments for restricted share vesting		$ (1.3)			(1.3)
Vesting of restricted shares granted from treasury stock					1.0			$ (1.0)
Vesting of restricted shares granted from treasury (in shares)								0
Stock Repurchased During Period, Shares		200,000						200,000
Stock Repurchased During Period, Value		$ (11.9)						$ (11.9)
Equity-based compensation expense		12.1			12.1
Net earnings		32.6				32.6
Equity-based compensation expense of unconsolidated affiliates		0.6				0.6
Foreign currency translation adjustment	[1]	0.0
Unrealized gains on interest rate swaps, net		(12.1)					(12.1)
Unrealized loss on investments in unconsolidated affiliates		(2.2)	[2]				(2.2)
Ending balance at Jun. 30, 2019		1,825.6			1,567.3	439.3	(20.1)	$ (160.9)
Ending balance (in shares) at Jun. 30, 2019				153,100,000				3,400,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance (in shares)				153,100,000				3,400,000
Beginning balance (in shares)				153,100,000				3,400,000
Cumulative effect of new accounting principle		(1.1)
Cumulative effect of new accounting principle | Accounting Standards Update 2016-13 [Member]						(1.1)
Beginning balance, adjusted		1,897.4			1,586.8	489.5	(20.2)	$ (158.7)
Beginning balance at Dec. 31, 2019		1,898.5			1,586.8	490.6	(20.2)	$ (158.7)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance (in shares)				153,000,000.0				3,000,000.0
Issuance of common stock, net of underwriters' discount and issuance costs (shares)				7,100,000
Ending balance at Mar. 31, 2020		1,919.6			1,562.7	540.0	(41.0)	$ (142.1)
Ending balance (in shares) at Mar. 31, 2020				153,000,000.0				3,000,000.0
Beginning balance at Dec. 31, 2019		1,898.5			1,586.8	490.6	(20.2)	$ (158.7)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance (in shares)				160,100,000				3,000,000.0
Issuance of common stock, net of underwriters' discount and issuance costs (shares)				7,100,000
Issuance of common stock, net of underwriters' discount and issuance costs		$ 484.2			484.2
Grant of restricted shares of common stock (in shares)								(500,000)
Grant of restricted shares of common stock					(24.6)			$ 24.6
Forfeitures of restricted shares of common stock					0.3			$ (0.3)
Tax withholding payments for restricted share vesting (in shares)		100,000						100,000
Tax withholding payments for restricted share vesting		$ (19.7)			(19.7)
Vesting of restricted shares granted from treasury stock					8.7			$ (8.7)
Stock Repurchased During Period, Shares		0
Equity-based compensation expense		$ 20.2			20.2
Net earnings		89.2				89.2
Equity-based compensation expense of unconsolidated affiliates		3.6				3.6
Foreign currency translation adjustment		(0.2)	[1]				(0.2)
Unrealized gains on interest rate swaps, net		(19.8)					(19.8)
Unrealized loss on investments in unconsolidated affiliates		(1.7)	[2]				(1.7)
Ending balance at Jun. 30, 2020		2,453.2			2,055.9	582.3	(41.9)	$ (143.1)
Ending balance (in shares) at Jun. 30, 2020				160,100,000				3,000,000.0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance (in shares)				153,000,000.0				3,000,000.0
Beginning balance at Mar. 31, 2020		1,919.6			1,562.7	540.0	(41.0)	$ (142.1)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance (in shares)				160,100,000				3,000,000.0
Issuance of common stock, net of underwriters' discount and issuance costs		484.2			484.2
Grant of restricted shares of common stock (in shares)								0
Grant of restricted shares of common stock					(0.1)			$ 0.1
Forfeitures of restricted shares of common stock					0.1			(0.1)
Tax withholding payments for restricted share vesting (in shares)				0
Tax withholding payments for restricted share vesting		(1.5)			(1.5)
Vesting of restricted shares granted from treasury stock					1.0			$ (1.0)
Vesting of restricted shares granted from treasury (in shares)
Equity-based compensation expense		9.5			9.5
Net earnings		39.1				39.1
Equity-based compensation expense of unconsolidated affiliates		3.2				3.2
Foreign currency translation adjustment	[1]	0.0
Unrealized gains on interest rate swaps, net		0.6					0.6
Unrealized loss on investments in unconsolidated affiliates		(1.5)	[2]				(1.5)
Ending balance at Jun. 30, 2020		$ 2,453.2			$ 2,055.9	$ 582.3	$ (41.9)	$ (143.1)
Ending balance (in shares) at Jun. 30, 2020				160,100,000				3,000,000.0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance (in shares)				160,100,000				3,000,000.0

[1] Net of income tax benefit of $0.1 million for the six months ended June 30, 2020

[2] Net of income tax benefit of $0.5 million and $0.6 million for the three and six months ended June 30, 2020, respectively, and $0.8 million and $0.9 million for the three and six months ended June 30, 2019, respectively.