Equity and Accumulated Other Comprehensive Loss, Net (Redeemable Preferred Stock) (Details) $ / shares in Units, $ in Thousands						12 Months Ended
	Sep. 14, 2017 $ / shares shares	Aug. 07, 2017 $ / shares shares	Aug. 24, 2015 $ / shares shares	Mar. 26, 2014 $ / shares shares	Apr. 09, 2013 $ / shares shares	Dec. 31, 2018 USD ($) quarter $ / shares shares	Dec. 31, 2017 USD ($) $ / shares shares	Apr. 05, 2017 $ / shares
Class of Stock [Line Items]
Liquidation preference						$ 1,266,250	$ 1,266,250
Shares outstanding (in shares) | shares						50,650,000	50,650,000
Balance (net of issuance costs) as of December 31						$ 1,249,560	$ 1,249,560
Number of quarters with no dividends triggering voting rights | quarter						6
Preferred stock, liquidation preference per share (in dollars per share) | $ / shares						$ 25.00	$ 25.00
Series C Preferred Stock
Class of Stock [Line Items]
Share cap (in shares) | shares	0.6389035
Liquidation preference						$ 201,250
Annual rate of dividend per share (in dollars per share) | $ / shares	$ 1.65625					$ 1.65625
Shares outstanding (in shares) | shares						8,050,000	8,050,000
Balance (net of issuance costs) as of December 31						$ 219,250	$ 219,250
Preferred stock dividend rate	6.625%
Series G Preferred Stock
Class of Stock [Line Items]
Share cap (in shares) | shares					0.7532
Liquidation preference						$ 250,000
Annual rate of dividend per share (in dollars per share) | $ / shares					$ 1.46875	$ 1.46875
Shares outstanding (in shares) | shares						10,000,000	10,000,000
Balance (net of issuance costs) as of December 31						$ 241,468	$ 241,468
Preferred stock dividend rate					5.875%
Series H Preferred Stock
Class of Stock [Line Items]
Share cap (in shares) | shares				0.9632
Liquidation preference						$ 365,000
Annual rate of dividend per share (in dollars per share) | $ / shares				$ 1.84375		$ 1.84375
Shares outstanding (in shares) | shares						14,600,000	14,600,000
Balance (net of issuance costs) as of December 31						$ 353,290	$ 353,290
Preferred stock dividend rate				7.375%
Series I Preferred Stock
Class of Stock [Line Items]
Share cap (in shares) | shares			0.76231
Liquidation preference						$ 250,000
Annual rate of dividend per share (in dollars per share) | $ / shares			$ 1.58750			$ 1.5875
Shares outstanding (in shares) | shares						10,000,000	10,000,000
Balance (net of issuance costs) as of December 31						$ 242,012	$ 242,012
Preferred stock dividend rate			6.35%
Series J Preferred Stock
Class of Stock [Line Items]
Share cap (in shares) | shares		0.42521
Liquidation preference						$ 200,000
Annual rate of dividend per share (in dollars per share) | $ / shares		$ 1.31250				$ 1.3125
Shares outstanding (in shares) | shares						8,000,000	8,000,000
Balance (net of issuance costs) as of December 31						$ 193,540	$ 193,540
Preferred stock dividend rate		5.25%
Series F Preferred Stock
Class of Stock [Line Items]
Annual rate of dividend per share (in dollars per share) | $ / shares						$ 1.65625
Preferred stock, liquidation preference per share (in dollars per share) | $ / shares								$ 25.00