Earnings Per Common Share - Basic and Diluted Net Income Per Common Unit (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Basic
Net income (loss) attributable to common shares	$ 295,500,000	$ 68,400,000	$ (170,600,000)	$ 353,600,000
Weighted-average common shares outstanding (in shares)	351,567,631	114,930,365	349,468,329	111,547,969
Net income (loss) per common share (usd per share)	$ 0.84	$ 0.60	$ (0.49)	$ 3.17
Diluted
Net income attributable to common shares	$ 295,500,000	$ 68,400,000	$ (170,600,000)	$ 353,600,000
Weighted-average common shares outstanding (in shares)	358,405,845	124,875,070	349,468,329	120,558,967
Net income (loss) per common share (usd per share)	$ 0.82	$ 0.55	$ (0.49)	$ 2.93