Equity and Capital - Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2017
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets			$ 12
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	$ (5,154)	$ 9,003
Accumulated Other Comprehensive Income Loss [Roll Forward]
Beginning balance	(805)	(6,262)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	(152)	2,157
Current period other comprehensive income, net	(5,306)	11,160
Ending balance	(6,111)	4,910
Accumulated Net Unrealized Investment Gain (Loss) [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets			0
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	137	(119)
Accumulated Other Comprehensive Income Loss [Roll Forward]
Beginning balance	(122)	(27)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	0	0
Current period other comprehensive income, net	137	(119)
Ending balance	15	(146)
Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets			12
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	(5,017)	8,884
Accumulated Other Comprehensive Income Loss [Roll Forward]
Beginning balance	(927)	(6,289)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	(152)	2,157
Current period other comprehensive income, net	(5,169)	11,041
Ending balance	(6,096)	4,764
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Noncontrolling Interest [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets			2
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	(335)	502
Accumulated Other Comprehensive Income Loss [Roll Forward]
Beginning balance	189	(112)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	(24)	(19)
Current period other comprehensive income, net	(359)	483
Ending balance	(170)	373
AOCI Attributable to Noncontrolling Interest [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets			2
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	(335)	502
Accumulated Other Comprehensive Income Loss [Roll Forward]
Beginning balance	189	(112)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	(24)	(19)
Current period other comprehensive income, net	(359)	483
Ending balance	(170)	373
AOCI Including Portion Attributable to Noncontrolling Interest [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets			$ 14
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	(5,352)	9,386
Accumulated Other Comprehensive Income Loss [Roll Forward]
Beginning balance	(738)	(6,401)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	(176)	2,138
Current period other comprehensive income, net	(5,528)	11,524
Ending balance	$ (6,266)	5,137
Accounting Standards Update 2017-12 [Member] | Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income Loss [Roll Forward]
Beginning balance		(6,250)
Accounting Standards Update 2017-12 [Member] | Accumulated Net Unrealized Investment Gain (Loss) [Member]
Accumulated Other Comprehensive Income Loss [Roll Forward]
Beginning balance		(27)
Accounting Standards Update 2017-12 [Member] | Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income Loss [Roll Forward]
Beginning balance		(6,277)
Accounting Standards Update 2017-12 [Member] | Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Noncontrolling Interest [Member]
Accumulated Other Comprehensive Income Loss [Roll Forward]
Beginning balance		(110)
Accounting Standards Update 2017-12 [Member] | AOCI Attributable to Noncontrolling Interest [Member]
Accumulated Other Comprehensive Income Loss [Roll Forward]
Beginning balance		(110)
Accounting Standards Update 2017-12 [Member] | AOCI Including Portion Attributable to Noncontrolling Interest [Member]
Accumulated Other Comprehensive Income Loss [Roll Forward]
Beginning balance		$ (6,387)