Summary of Quarterly Financial Data (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014
Revenues included in Discontinued Operations				$ 140,399
Net income (loss) attributable to common stockholders	$ 17,609	$ 53,731	$ 32,480	25,174	$ 73,515	$ 47,942	$ 25,482	$ 19,389
Noncontrolling Interest in Net Income (Loss) Operating Partnerships, Nonredeemable	36	94	61	49	134	90	53	42
Net Income (Loss) Attributable to Common Unit Holders	$ 17,645	$ 53,825	$ 32,541	$ 25,223	$ 73,649	$ 48,032	$ 25,535	$ 19,431
Earnings Per Share, Basic	$ 0.18	$ 0.57	$ 0.35	$ 0.27	$ 0.79	$ 0.52	$ 0.28	$ 0.21
Earnings Per Share, Diluted	$ 0.18	$ 0.57	$ 0.34	$ 0.27	$ 0.79	$ 0.52	$ 0.28	$ 0.21
Scenario, Previously Reported [Member]
Revenues included in Discontinued Operations	$ 146,167	$ 142,068	$ 141,129		$ 136,167	$ 133,559	$ 134,892	$ 133,280