Equity and Accumulated Other Comprehensive Loss, Net (Schedule of Dividends) (Details) - USD ($) $ / shares in Units, $ in Thousands									12 Months Ended
	Sep. 14, 2017	Aug. 07, 2017	Apr. 05, 2017	Sep. 15, 2016	Aug. 24, 2015	Mar. 26, 2014	Apr. 09, 2013	Apr. 05, 2012	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Dividends Payable [Line Items]
Preferred stock, liquidation preference per share/unit (in dollars per share)									$ 25.00
Series C Preferred Stock
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units									$ 3,963	$ 0	$ 0
Annual rate of dividend per share (in dollars per share)	$ 1.65625								$ 1.65625
Share cap (in shares)	0.6389035
Series C Preferred Stock | February 25, 2015
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units											0
Series C Preferred Stock | May 12, 2015
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units											0
Series C Preferred Stock | August 11, 2015
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units											0
Series C Preferred Stock | November 12, 2015
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units											0
Series C Preferred Stock | February 17, 2016
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units										0
Series C Preferred Stock | May 11, 2016
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units										0
Series C Preferred Stock | August 10, 2016
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units										0
Series C Preferred Stock | November 9, 2016
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units										0
Series C Preferred Stock | March 1, 2017
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units									$ 0
Series C Preferred Stock | May 8, 2017
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units									0
Series C Preferred Stock | August 7, 2017
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units									0
Series C Preferred Stock | November 2, 2017
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units									3,963
Series E Preferred Units
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units									$ 0	10,062	20,124
Annual rate of dividend per share (in dollars per share)									$ 1.75
Preferred stock, redemption price per share (in dollars per share)				$ 25.35972
Preferred stock, liquidation preference per share/unit (in dollars per share)				$ 25.00
Accrued and unpaid dividends up to but not including the redemption date				$ 4,100
Redemption premium				$ 10,300
Series E Preferred Units | February 25, 2015
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units											5,031
Series E Preferred Units | May 12, 2015
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units											5,031
Series E Preferred Units | August 11, 2015
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units											5,031
Series E Preferred Units | November 12, 2015
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units											5,031
Series E Preferred Units | February 17, 2016
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units										5,031
Series E Preferred Units | May 11, 2016
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units										5,031
Series E Preferred Units | August 10, 2016
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units										0
Series E Preferred Units | November 9, 2016
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units										0
Series E Preferred Units | March 1, 2017
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units									$ 0
Series E Preferred Units | May 8, 2017
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units									0
Series E Preferred Units | August 7, 2017
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units									0
Series E Preferred Units | November 2, 2017
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units									0
Series F Preferred Stock
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units									$ 3,023	12,092	12,092
Annual rate of dividend per share (in dollars per share)								$ 1.65625	$ 1.65625
Share cap (in shares)								0.6843
Preferred stock, redemption price per share (in dollars per share)			$ 25.01840
Preferred stock, liquidation preference per share/unit (in dollars per share)			$ 25.00
Accrued and unpaid dividends up to but not including the redemption date			$ 100
Redemption premium			$ 6,300
Series F Preferred Stock | February 25, 2015
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units											3,023
Series F Preferred Stock | May 12, 2015
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units											3,023
Series F Preferred Stock | August 11, 2015
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units											3,023
Series F Preferred Stock | November 12, 2015
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units											3,023
Series F Preferred Stock | February 17, 2016
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units										3,023
Series F Preferred Stock | May 11, 2016
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units										3,023
Series F Preferred Stock | August 10, 2016
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units										3,023
Series F Preferred Stock | November 9, 2016
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units										3,023
Series F Preferred Stock | March 1, 2017
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units									$ 3,023
Series F Preferred Stock | May 8, 2017
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units									0
Series F Preferred Stock | August 7, 2017
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units									0
Series F Preferred Stock | November 2, 2017
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units									0
Series G Preferred Stock and Unit
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units									$ 14,688	14,688	14,688
Annual rate of dividend per share (in dollars per share)							$ 1.46875		$ 1.46875
Share cap (in shares)							0.7532
Series G Preferred Stock and Unit | February 25, 2015
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units											3,672
Series G Preferred Stock and Unit | May 12, 2015
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units											3,672
Series G Preferred Stock and Unit | August 11, 2015
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units											3,672
Series G Preferred Stock and Unit | November 12, 2015
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units											3,672
Series G Preferred Stock and Unit | February 17, 2016
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units										3,672
Series G Preferred Stock and Unit | May 11, 2016
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units										3,672
Series G Preferred Stock and Unit | August 10, 2016
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units										3,672
Series G Preferred Stock and Unit | November 9, 2016
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units										3,672
Series G Preferred Stock and Unit | March 1, 2017
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units									$ 3,672
Series G Preferred Stock and Unit | May 8, 2017
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units									3,672
Series G Preferred Stock and Unit | August 7, 2017
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units									3,672
Series G Preferred Stock and Unit | November 2, 2017
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units									3,672
Series H Preferred Stock and Unit
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units									$ 26,920	26,920	26,920
Annual rate of dividend per share (in dollars per share)						$ 1.84375			$ 1.84375
Share cap (in shares)						0.9632
Series H Preferred Stock and Unit | February 25, 2015
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units											6,730
Series H Preferred Stock and Unit | May 12, 2015
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units											6,730
Series H Preferred Stock and Unit | August 11, 2015
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units											6,730
Series H Preferred Stock and Unit | November 12, 2015
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units											6,730
Series H Preferred Stock and Unit | February 17, 2016
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units										6,730
Series H Preferred Stock and Unit | May 11, 2016
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units										6,730
Series H Preferred Stock and Unit | August 10, 2016
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units										6,730
Series H Preferred Stock and Unit | November 9, 2016
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units										6,730
Series H Preferred Stock and Unit | March 1, 2017
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units									$ 6,730
Series H Preferred Stock and Unit | May 8, 2017
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units									6,730
Series H Preferred Stock and Unit | August 7, 2017
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units									6,730
Series H Preferred Stock and Unit | November 2, 2017
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units									6,730
Series I Preferred Stock and Unit
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units									$ 15,876	15,876	5,600
Annual rate of dividend per share (in dollars per share)					$ 1.58750				$ 1.5875
Share cap (in shares)					0.76231
Series I Preferred Stock and Unit | February 25, 2015
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units											0
Series I Preferred Stock and Unit | May 12, 2015
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units											0
Series I Preferred Stock and Unit | August 11, 2015
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units											0
Series I Preferred Stock and Unit | November 12, 2015
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units											5,600
Series I Preferred Stock and Unit | February 17, 2016
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units										3,969
Series I Preferred Stock and Unit | May 11, 2016
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units										3,969
Series I Preferred Stock and Unit | August 10, 2016
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units										3,969
Series I Preferred Stock and Unit | November 9, 2016
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units										3,969
Series I Preferred Stock and Unit | March 1, 2017
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units									$ 3,969
Series I Preferred Stock and Unit | May 8, 2017
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units									3,969
Series I Preferred Stock and Unit | August 7, 2017
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units									3,969
Series I Preferred Stock and Unit | November 2, 2017
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units									3,969
Series J Preferred Stock
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units									$ 4,200	0	0
Annual rate of dividend per share (in dollars per share)		$ 1.31250							$ 1.3125
Share cap (in shares)		0.42521
Series J Preferred Stock | February 25, 2015
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units											0
Series J Preferred Stock | May 12, 2015
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units											0
Series J Preferred Stock | August 11, 2015
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units											0
Series J Preferred Stock | November 12, 2015
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units											0
Series J Preferred Stock | February 17, 2016
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units										0
Series J Preferred Stock | May 11, 2016
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units										0
Series J Preferred Stock | August 10, 2016
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units										0
Series J Preferred Stock | November 9, 2016
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units										0
Series J Preferred Stock | March 1, 2017
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units									$ 0
Series J Preferred Stock | May 8, 2017
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units									0
Series J Preferred Stock | August 7, 2017
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units									0
Series J Preferred Stock | November 2, 2017
Dividends Payable [Line Items]
Dividends/Distributions, preferred stock/units									4,200
Common Stock
Dividends Payable [Line Items]
Dividends/Distributions, common stock/units									$ 681,280	536,733	$ 470,748
Common stock dividend per share amount (in dollars per share)											$ 3.400
Common Stock | February 25, 2015
Dividends Payable [Line Items]
Dividends/Distributions, common stock/units											$ 115,419
Common Stock | May 12, 2015
Dividends Payable [Line Items]
Dividends/Distributions, common stock/units											115,458
Common Stock | August 11, 2015
Dividends Payable [Line Items]
Dividends/Distributions, common stock/units											115,454
Common Stock | November 12, 2015
Dividends Payable [Line Items]
Dividends/Distributions, common stock/units											$ 124,417
Common Stock | February 17, 2016
Dividends Payable [Line Items]
Dividends/Distributions, common stock/units										131,587
Common Stock | May 11, 2016
Dividends Payable [Line Items]
Dividends/Distributions, common stock/units										131,607
Common Stock | August 10, 2016
Dividends Payable [Line Items]
Dividends/Distributions, common stock/units										131,657
Common Stock | November 9, 2016
Dividends Payable [Line Items]
Dividends/Distributions, common stock/units										$ 141,882
Common stock dividend per share amount (in dollars per share)									$ 3.720	$ 3.520
Common Stock | March 1, 2017
Dividends Payable [Line Items]
Dividends/Distributions, common stock/units									$ 148,358
Common Stock | May 8, 2017
Dividends Payable [Line Items]
Dividends/Distributions, common stock/units									150,814
Common Stock | August 7, 2017
Dividends Payable [Line Items]
Dividends/Distributions, common stock/units									191,041
Common Stock | November 2, 2017
Dividends Payable [Line Items]
Dividends/Distributions, common stock/units									$ 191,067