Earnings per Share and Unit (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Income per common unit - diluted
Weighted Average Limited Partnership Units Outstanding, Basic	349,902		276,503	154,170
Parent Company [Member]
Earnings Per Share [Abstract]
Net income attributable to common stockholders	$ 59,666	$ 5,305	$ 74,810	$ 87,992
Weighted average common units outstanding for basic EPU (in shares)	170,105,000	103,675,000	155,881,000	99,639,000
Weighted average common units outstanding for diluted EPU (in shares)	170,466,000	104,255,000	156,190,000	100,128,000
Income per common share/unit - basic:
Continuing operations (in dollars per share)	$ 0.35	$ 0.05	$ 0.48	$ 0.88
Income per common share/unit - diluted:
Continuing operations (in dollars per share)	$ 0.35	$ 0.05	$ 0.48	$ 0.88
Partnership Interest [Member]
Earnings Per Share [Abstract]
Weighted average common units outstanding for basic EPU (in shares)	170,455,000	103,829,000	156,158,000	99,793,000
Weighted average common units outstanding for diluted EPU (in shares)	170,816,000	104,409,000	156,467,000	100,282,000
Income per common unit - basic
Continuing operations (in dollars per share)	$ 0.35	$ 0.05	$ 0.48	$ 0.88
Income per common unit - diluted
Continuing operations (in dollars per share)	$ 0.35	$ 0.05	$ 0.48	$ 0.88
Continuing Operations [Member] | Parent Company [Member]
Earnings Per Share [Abstract]
Net income attributable to common stockholders	$ 59,666	$ 5,305	$ 74,810	$ 87,992
Net income for common stock unit/holders - diluted	59,666	5,305	74,810	87,992
Continuing Operations [Member] | Partnership Interest [Member]
Earnings Per Share [Abstract]
Net income attributable to common stockholders	59,798	5,321	75,027	88,157
Net income for common stock unit/holders - diluted	$ 59,798	$ 5,321	$ 75,027	$ 88,157