Equity and Capital Equity and Capital - Common Stock (Details) - USD ($)				1 Months Ended		12 Months Ended
	Feb. 29, 2020	Feb. 04, 2020	Jan. 31, 2019	Dec. 31, 2019	Sep. 30, 2019	Dec. 31, 2019	Dec. 31, 2018
Class of Stock [Line Items]
Common stock remaining available for Issuance				500,000,000		500,000,000
Stock Repurchase Program, Authorized Amount		$ 250,000,000
Stock Repurchase Program Expiration Date		Feb. 05, 2021
Stock Repurchased and Retired During Period, Value						$ (32,778,000)	$ (213,851,000)
Common Stock [Member]
Class of Stock [Line Items]
Stock Repurchased and Retired During Period, Shares	0		563,229
Stock Repurchased and Retired During Period, Value			$ (32,800,000)			$ (6,000)	$ (37,000)
Common Stock [Member] | Average share price [Member]
Class of Stock [Line Items]
Stock Repurchased and Retired During Period, Value Per Share			$ (58.17)
ATM Equity Offering Program [Member]
Class of Stock [Line Items]
Shares issued under program							0
ATM Equity Offering Program [Member] | Forward Equity Offering [Member]
Class of Stock [Line Items]
Number of shares issuable					1,894,845
Sale of stock, average offering price					$ 67.99
Settlement date					Sep. 12, 2020
ATM Equity Offering Program [Member] | Forward Equity Offering [Member] | Parent Company [Member]
Class of Stock [Line Items]
Number of shares settled				0
Maximum [Member]
Class of Stock [Line Items]
Equity Issuances, Common Shares Authorized for Issuance				500,000,000.0		500,000,000.0