Equity - Reclassifications out of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Investment fair value changes, net	$ (324)	$ (11,918)	$ (9,990)	$ 18,686
Realized gains, net	(1,734)	(6,615)	(8,809)	(26,037)
Interest expense	27,443	21,597	72,708	67,991
Net Income before Provision for Income Taxes	(41,442)	(53,525)	(126,214)	(107,224)
Other than temporary impairment recognized in AOCI	0		400	2,000
Reclassification out of Accumulated Other Comprehensive Income \| Net Unrealized Gains on Available-for-Sale Securities
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Investment fair value changes, net	3	0	248	(3,000)
Other than temporary impairment			600	(305)
Realized gains, net	(856)	(1,319)	(7,351)	(20,288)
Net Income before Provision for Income Taxes	(853)	(1,319)	(7,103)	(19,983)
Reclassification out of Accumulated Other Comprehensive Income \| Net Unrealized Losses on Interest Rate Agreements Accounted for as Cash Flow Hedges
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net Income before Provision for Income Taxes	14	18	42	55
Reclassification out of Accumulated Other Comprehensive Income \| Net Unrealized Losses on Interest Rate Agreements Accounted for as Cash Flow Hedges \| Interest rate contract
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest expense	$ 14	$ 18	$ 42	$ 55

Amount of income (loss) from continuing operations before deduction of income tax expense (benefit) and income (loss) attributable to noncontrolling interest, and addition of income (loss) from equity method investments.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(h)(1)(i))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

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Amount of the cost of borrowed funds accounted for as interest expense.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6450988&loc=d3e26243-108391

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-Publisher FASB
-Name Accounting Standards Codification
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-Section S99
-Paragraph 1
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Amount before tax of other than temporary impairment (OTTI) loss on investments in available-for-sale and held-to-maturity debt securities, recognized in other comprehensive loss.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 10A
-Subparagraph (g)
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The amount of other than temporary impairment (OTTI) losses on equity securities, OTTI related to credit losses on debt securities, and OTTI losses on debt securities when the entity intends to sell the securities or it is more likely than not that the entity will be required to sell the securities before recovery of its amortized cost basis. Additionally, this item includes OTTI losses recognized during the period on investments accounted for under the cost method of accounting.

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The net realized gains or losses on investments during the period, not including gains or losses on securities separately or otherwise categorized as trading, available-for-sale, or held-to-maturity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
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The net change in the difference between the fair value and the carrying value, or in the comparative fair values, of investments, not including unrealized gains or losses on securities separately or otherwise categorized as trading, available-for-sale, or held-to-maturity, held at each balance sheet date and included in earnings for the period.

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