Capital and Accumulated Other Comprehensive Loss (5.850% Series K Cumulative Redeemable Preferred Stock) (Details) - $ / shares	Jun. 29, 2019	Mar. 13, 2019	Mar. 31, 2019	Mar. 15, 2019	Dec. 31, 2018
Class of Stock [Line Items]
Preferred stock, issued (shares)			59,050,000		50,650,000
Series K Preferred Units
Class of Stock [Line Items]
Dividend rate percentage		5.85%
Redemption price (in dollars per share)				$ 25.00
Preferred stock dividend per share amount (in dollars per share)		$ 1.46250
Preferred stock, issued (shares)		8,400,000
Scenario, Forecast | Series K Preferred Units
Class of Stock [Line Items]
Preferred stock dividend per share amount (in dollars per share)	$ 0.43875