Equity and Capital - Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Accumulated Other Comprehensive Income Loss [Roll Forward]
Current period other comprehensive income, net			$ 22,815	$ (4,693)
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax			(25,015)	(11,022)
Accumulated Other Comprehensive Income Loss [Roll Forward]
Beginning balance			(58,650)	(57,748)
Current period other comprehensive income, net			22,865	(4,486)
Ending balance	$ (35,785)	$ (62,234)	(35,785)	(62,234)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax			47,880	6,536
Accumulated Net Investment Gain (Loss) Attributable to Noncontrolling Interest [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax			0	0
Accumulated Other Comprehensive Income Loss [Roll Forward]
Beginning balance			0	0
Current period other comprehensive income, net			0	0
Ending balance	0	0	0	0
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax			0	0
AOCI Attributable to Noncontrolling Interest [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax			(322)	(252)
Accumulated Other Comprehensive Income Loss [Roll Forward]
Beginning balance			(785)	(750)
Current period other comprehensive income, net			(139)	(134)
Ending balance	(924)	(884)	(924)	(884)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax			183	118
AOCI Including Portion Attributable to Noncontrolling Interest [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax			(25,248)	(11,347)
Accumulated Other Comprehensive Income Loss [Roll Forward]
Beginning balance			(59,478)	(58,498)
Current period other comprehensive income, net			22,815	(4,693)
Ending balance	(36,663)	(63,191)	(36,663)	(63,191)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	43,111	2,155	48,063	6,654
Accumulated Net Unrealized Investment Gain (Loss) [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax			89	(73)
Accumulated Other Comprehensive Income Loss [Roll Forward]
Beginning balance			(43)	0
Current period other comprehensive income, net			89	(73)
Ending balance	46	(73)	46	(73)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax			0	0
Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax			(24,926)	(11,095)
Accumulated Other Comprehensive Income Loss [Roll Forward]
Beginning balance			(58,693)	(57,748)
Current period other comprehensive income, net			22,954	(4,559)
Ending balance	(35,739)	(62,307)	(35,739)	(62,307)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax			47,880	6,536
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Noncontrolling Interest [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax			(322)	(252)
Accumulated Other Comprehensive Income Loss [Roll Forward]
Beginning balance			(785)	(750)
Current period other comprehensive income, net			(139)	(134)
Ending balance	(924)	(884)	(924)	(884)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax			183	118
Partnership Interest [Member]
Accumulated Other Comprehensive Income Loss [Roll Forward]
Beginning balance			(58,693)
Current period other comprehensive income, net	44,458	$ (13,656)	22,815	$ (4,693)
Ending balance	$ (35,739)		$ (35,739)