Summary of Significant Accounting Policies (Details 6) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended									12 Months Ended
	Dec. 31, 2015 USD ($) $ / shares	Sep. 30, 2015 USD ($) $ / shares	Jun. 30, 2015 USD ($) $ / shares	Mar. 31, 2015 USD ($) $ / shares	Dec. 31, 2014 USD ($) $ / shares	Sep. 30, 2014 USD ($) $ / shares	Jun. 30, 2014 USD ($) $ / shares	Mar. 31, 2014 USD ($) $ / shares	Mar. 31, 2013	Dec. 31, 2015 USD ($) segment $ / shares shares	Dec. 31, 2014 USD ($) $ / shares shares	Dec. 31, 2013 USD ($) $ / shares shares
Numerator:
Net income	$ 237,575	$ 63,084	$ 53,657	$ 1,203	$ 14,257	$ 33,643	$ 43,535	$ (3,496)		$ 355,519	$ 87,939	$ 70,001
Income from consolidated joint ventures attributable to noncontrolling interests										(8,164)	(6,708)	(4,045)
Preferred stock dividends and redemption charges										(9,200)	(9,200)	(19,013)
Dividends paid on unvested restricted stock compensation										(1,405)	(969)	(201)
Undistributed income allocated to unvested restricted stock compensation										(155)		(235)
Numerator for basic and diluted income attributable to common stockholders										$ 336,595	$ 71,062	$ 46,507
Denominator:
Weighted average basic and diluted common shares outstanding (in shares) | shares										207,350	192,674	161,784
Basic and diluted income attributable to common stockholders per common share (in dollars per share) | $ / shares	$ 1.12	$ 0.28	$ 0.23	$ (0.02)	$ 0.05	$ 0.14	$ 0.22	$ (0.04)		$ 1.62	$ 0.37	$ 0.29
Segment Reporting
Number of operating segments | segment										1
Series D Cumulative Redeemable Preferred Stock
Summary Of Significant Accounting Policies [Line Items]
Dividend rate (as a percent)										8.00%	8.00%
Series A Cumulative Redeemable Preferred Stock
Summary Of Significant Accounting Policies [Line Items]
Dividend rate (as a percent)									8.00%