Subsequent Event (Details) - USD ($) $ / shares in Units, $ in Millions					1 Months Ended	3 Months Ended
	Aug. 12, 2021	Jul. 16, 2021	Jun. 30, 2021	Dec. 31, 2020	May 31, 2016	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2020	Mar. 31, 2020	Aug. 13, 2021	Jul. 01, 2021	May 31, 2021
Series F Cumulative Redeemable Preferred Stock
Stockholders' equity
Number of shares of preferred stock issued (in shares)					3,000,000
Preferred stock, Cumulative Redeemable Preferred Stock, dividend rate (as a percent)			6.45%	6.45%	6.45%
Liquidation preference (in dollars per share)			$ 25.00	$ 25.00	$ 25.00	$ 25.00
Redemption price (in dollars per share)												$ 25.00
Preferred stock dividends accrued and unpaid (in dollars per share)						$ 0.403125	$ 0.403125	$ 0.403125	$ 0.403125
Preferred stock, Cumulative Redeemable Preferred Stock, shares outstanding (in shares)			3,000,000	3,000,000		3,000,000
Subsequent Event [Member]
Business Combination, Description [Abstract]
Cancellable contract purchase price											$ 200.0
Subsequent Event [Member] | Series I Cumulative Redeemable Preferred Stock
Stockholders' equity
Number of shares of preferred stock issued (in shares)		4,000,000
Preferred stock, Cumulative Redeemable Preferred Stock, dividend rate (as a percent)		5.70%
Liquidation preference (in dollars per share)		$ 25.00
Preferred stock redemption date		Jul. 16, 2026
Redemption price (in dollars per share)		$ 25.00
Subsequent Event [Member] | Series F Cumulative Redeemable Preferred Stock
Stockholders' equity
Redemption price (in dollars per share)	$ 25.00
Number of shares redeemed (in shares)	3,000,000
Preferred stock dividends accrued and unpaid (in dollars per share)	$ 0.183646
Redemption amount including accrued and unpaid dividends (in dollars per share)	25.183646
Preferred stock, Cumulative Redeemable Preferred Stock, shares outstanding (in shares)										0