CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Statement of Comprehensive Income [Abstract]
Net income	$ 18,104	$ 111,072	$ 142,099	$ 142,055
Other comprehensive income (loss)
Unrealized loss on valuation of swap agreements	(5,671)	(81)	(7,328)	(5,189)
Reclassification of realized interest on swap agreements	1,026	961	4,478	2,734
Other comprehensive (loss) income	(4,645)	880	(2,850)	(2,455)
Comprehensive income	13,459	111,952	139,249	139,600
Comprehensive income attributable to noncontrolling interests	(3,743)	(82,864)	(85,772)	(80,663)
Comprehensive income attributable to Common Shareholders	$ 9,716	$ 29,088	$ 53,477	$ 58,937