Shareholders' Equity, Noncontrolling Interests and Other Comprehensive Income - Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Balance	$ 2,178,125	$ 1,521,354
Net current period other comprehensive income	1,081	(7,773)
Balance	2,196,493	1,628,476
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Balance	(798)	(4,463)
Other comprehensive loss before reclassifications	118	(8,818)
Reclassification of realized interest on swap agreements	963	1,046
Net current period other comprehensive income	1,081	(7,772)
Balance	438	(11,467)
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Noncontrolling Interest [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net current period other comprehensive income	$ 155	$ 768