Equity and Capital - Redeemable Preferred Stock (Details) $ / shares in Units, $ in Thousands					12 Months Ended
	Oct. 10, 2019 shares	Mar. 13, 2019 shares	Sep. 14, 2017 $ / shares shares	Aug. 07, 2017 $ / shares shares	Dec. 31, 2021 USD ($) item $ / shares shares	Dec. 31, 2020 USD ($) $ / shares shares	May 17, 2021 $ / shares	Oct. 15, 2020 $ / shares	Sep. 08, 2020 $ / shares
Class of Stock
Liquidation preference | $					$ 755,000	$ 956,250
Preferred stock, issued (shares) | shares					30,200,000	38,250,000
Net proceeds from preferred stock | $					$ 731,690	$ 950,940
Number of quarters with no dividends triggering voting rights | item					6
Preferred stock, liquidation preference per share (in dollars per share)					$ 25.00	$ 25.00
Preferred Stock, Redemption Price Per Share					$ 25.00
Series C Cumulative Redeemable Perpetual Preferred Stock
Class of Stock
Share cap (in shares) | shares			0.6389035
Preferred stock dividend per share amount (in dollars per share)			$ 1.65625
Preferred stock, issued (shares) | shares						8,050,000
Net proceeds from preferred stock | $						$ 219,250
Dividend rate percentage			6.625%
Series J Cumulative Redeemable Preferred Stock
Class of Stock
Share cap (in shares) | shares				0.4252100
Liquidation preference | $					$ 200,000
Preferred stock dividend per share amount (in dollars per share)				$ 1.31250
Preferred stock, issued (shares) | shares					8,000,000	8,000,000
Net proceeds from preferred stock | $					$ 193,540	$ 193,540
Dividend rate percentage				5.25%
Series K Cumulative Redeemable Preferred Stock
Class of Stock
Share cap (in shares) | shares		0.4361100
Liquidation preference | $					$ 210,000
Preferred stock dividend per share amount (in dollars per share)					$ 1.46250
Preferred stock, issued (shares) | shares					8,400,000	8,400,000
Net proceeds from preferred stock | $					$ 203,264	$ 203,264
Dividend rate percentage		5.85%
Series L Cumulative Redeemable Preferred Units
Class of Stock
Share cap (in shares) | shares	0.3851800
Liquidation preference | $					$ 345,000
Preferred stock dividend per share amount (in dollars per share)					$ 1.30000
Preferred stock, issued (shares) | shares					13,800,000	13,800,000
Net proceeds from preferred stock | $					$ 334,886	$ 334,886
Dividend rate percentage	5.20%
Series C Preferred Units
Class of Stock
Preferred stock dividend per share amount (in dollars per share)					$ 1.65625
Preferred stock, liquidation preference per share (in dollars per share)							$ 25.211632
Preferred Stock, Redemption Price Per Share							$ 25.00
Series G Preferred Units
Class of Stock
Preferred stock dividend per share amount (in dollars per share)					1.46875
Preferred stock, liquidation preference per share (in dollars per share)								$ 25.057118
Preferred Stock, Redemption Price Per Share								$ 25.00
Series I Preferred Units
Class of Stock
Preferred stock dividend per share amount (in dollars per share)					1.58750
Preferred stock, liquidation preference per share (in dollars per share)									$ 25.29545
Preferred Stock, Redemption Price Per Share									$ 25.00
Series J Preferred Units
Class of Stock
Preferred stock dividend per share amount (in dollars per share)					1.31250
Series K Preferred Units
Class of Stock
Preferred stock dividend per share amount (in dollars per share)					1.46250
Series L Preferred Units
Class of Stock
Preferred stock dividend per share amount (in dollars per share)					$ 1.30000