Public Offering and Common Stock Repurchases - Narrative (Details) - USD ($)		3 Months Ended								12 Months Ended
		Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2018	Jan. 27, 2020	Dec. 07, 2016	Mar. 31, 2015
Equity, Class of Treasury Stock [Line Items]
Preferred stock under the if-converted method (in shares)										9,998,000	15,979,000	15,985,000
Dividends on preferred stock		$ 0	$ (2,800,000)	$ (5,800,000)	$ (5,800,000)	$ (5,800,000)	$ (5,800,000)	$ (5,800,000)	$ (5,800,000)	$ (14,400,000)	$ (23,200,000)	$ (23,200,000)
Repurchase of common stock	[1]									$ 100,700,000
Depositary Shares
Equity, Class of Treasury Stock [Line Items]
Shares issued (in shares)														8,100,000
Redeemable Convertible Preferred Stock
Equity, Class of Treasury Stock [Line Items]
Shares issued (in shares)		0				402,500				0	402,500			402,500
Offering price (in dollars per share)														$ 50
Shares converted (in shares)		402,500
Preferred stock under the if-converted method (in shares)		16,000,000.0
Dividends paid										$ 17,400,000	$ 23,200,000	$ 23,200,000
Common Stock
Equity, Class of Treasury Stock [Line Items]
Stock repurchase program, authorized amount (up to)													$ 300,000,000.0		$ 200,000,000.0
Stock repurchased during period, shares (in shares)										3,600,000	0	0
Repurchase of common stock										$ 100,700,000
Repurchase of common stock (in dollars per share)										$ 27.94
Stock repurchase program, remaining authorized repurchase amount		$ 223,000,000.0								$ 223,000,000.0

[1] During fiscal 2020, the Company repurchased and canceled 3.6 million shares of common stock at a total cost of $100.7 million at a weighted average price of $27.94 per share. See Note 19 Common Stock Purchases and Public Offerings for additional information