Shareholders' Equity, Noncontrolling Interests and Other Comprehensive Income - Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Balance	$ 1,521,354	$ 1,435,957	$ 1,121,588
Net current period other comprehensive income	3,930	463	(5,285)
Balance	2,178,125	1,521,354	1,435,957
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Balance	(4,463)	(4,005)	1,132
Other comprehensive loss before reclassifications	(646)	(5,061)	(9,061)
Reclassification of realized interest on swap agreements	4,576	5,524	3,776
Net current period other comprehensive income	3,930	463	(5,285)
Balance	(798)	(4,463)	(4,005)
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	$ (265)	$ (921)	$ 148