Stockholders' Equity - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized	11,800,000	11,800,000
Share-based Payment Arrangement, Nonvested Award, Excluding Option, Cost Not yet Recognized, Amount	$ 28.0	$ 28.0
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Outstanding Options, Weighted Average Remaining Contractual Term		2 years
Common Stock, Shares, Issued	108,981,341	108,981,341	103,013,290
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period		400,000	400,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number	900,000	900,000	1,000,000.0	1,000,000.0
Weighted Average Selling Price Per Share			$ 34.65
Stock Repurchase Program, Authorized Amount			$ 250.0
Stock Repurchased and Retired During Period, Shares			2,100,000
Stock Issued During Period, Value, New Issues		$ 540.3
Adjustments to Additional Paid in Capital, Stock Issued, Issuance Costs		2.3
Proceeds from issuance of common stock in offerings, net		$ 540.3	$ 0.0	$ 0.0
ATM Offering
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Issued During Period, Shares, New Issues		3,100,000
Stock Issued During Period, Value, New Issues		$ 333.4
Shares Issued, Price Per Share	$ 106.41	$ 106.41
Registered Direct Offering
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Issued During Period, Shares, New Issues		2,300,000
Shares Issued, Price Per Share	$ 91.00	$ 91.00
Proceeds from issuance of common stock in offerings, net		$ 209.2
Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Repurchased and Retired During Period, Shares			2,100,000	2,800,000
Stock Issued During Period, Shares, New Issues		5,400,000
Preferred Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Issued During Period, Shares, New Issues		12,000,000
Stock Issued During Period, Value, New Issues	$ 294.5	$ 294.5
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Payment Arrangement, Expense		10.4	$ 7.1	$ 6.9
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Payment Arrangement, Expense		$ 22.9	$ 20.3	$ 17.4
Grant year 2019 | Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number	203,646	203,646