Equity and Capital Equity and Capital - Common Stock (Details) - USD ($)	3 Months Ended		12 Months Ended	24 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Feb. 04, 2020	Feb. 06, 2020	Feb. 05, 2019	Feb. 07, 2018
Class of Stock [Line Items]
Stock Repurchase Program, Authorized Amount					$ 250,000,000	$ 250,000,000
Maximum [Member]
Class of Stock [Line Items]
Equity Issuances, Common Shares Authorized for Issuance	500,000,000
Parent Company [Member] | Common Stock [Member]
Class of Stock [Line Items]
Stock Repurchased and Retired During Period, Shares	563,229
Stock Repurchased and Retired During Period, Value	$ (32,778,000)	$ (124,989,000)
Parent Company [Member] | Common Stock [Member] | Accumulated Other Comprehensive Income (Loss) [Member]
Class of Stock [Line Items]
Stock Repurchased and Retired During Period, Value	0	$ 0
Parent Company [Member] | Common Stock [Member] | Average share price [Member]
Class of Stock [Line Items]
Stock Repurchased and Retired During Period, Value	$ (58.17)
Subsequent Event [Member]
Class of Stock [Line Items]
Stock Repurchase Program Expiration Date			Feb. 04, 2020	Feb. 06, 2020