Segment Information - Components of Corporate/Other (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Segment Reporting Information [Line Items]
Interest income	$ 150,117	$ 99,397	$ 429,700	$ 258,992
Interest expense	(116,604)	(64,351)	(332,100)	(154,078)
Net Interest Income	33,513	35,046	97,600	104,914
Investment fair value changes, net	11,444	10,332	34,741	12,830
Total non-interest income, net	27,498	32,284	101,771	91,471
Direct operating expenses	(26,815)	(21,490)	(76,229)	(63,529)
Net Income	34,310	40,921	120,040	120,513
Corporate/ Other
Segment Reporting Information [Line Items]
Interest income	4,732	5,414	15,086	15,702
Interest expense	(15,428)	(15,962)	(46,966)	(45,056)
Net Interest Income	(10,696)	(10,548)	(31,880)	(29,354)
Investment fair value changes, net	(452)	(234)	(1,008)	(926)
Other income	(236)	119	1,986	119
Total non-interest income, net	(688)	(115)	978	(807)
Direct operating expenses	(12,717)	(12,261)	(37,537)	(36,064)
Net Income	(24,101)	(22,924)	(68,439)	(66,225)
Corporate/ Other \| Legacy Consolidated VIEs
Segment Reporting Information [Line Items]
Interest income	4,295	5,174	13,924	15,003
Interest expense	(3,452)	(4,257)	(11,548)	(12,324)
Net Interest Income	843	917	2,376	2,679
Investment fair value changes, net	(407)	(248)	(904)	(976)
Other income	0	0	0	0
Total non-interest income, net	(407)	(248)	(904)	(976)
Direct operating expenses	0	0	0	0
Net Income	436	669	1,472	1,703
Corporate/ Other \| Other
Segment Reporting Information [Line Items]
Interest income	437	240	1,162	699
Interest expense	(11,976)	(11,705)	(35,418)	(32,732)
Net Interest Income	(11,539)	(11,465)	(34,256)	(32,033)
Investment fair value changes, net	(45)	14	(104)	50
Other income	(236)	119	1,986	119
Total non-interest income, net	(281)	133	1,882	169
Direct operating expenses	(12,717)	(12,261)	(37,537)	(36,064)
Net Income	$ (24,537)	$ (23,593)	$ (69,911)	$ (67,928)

Represents the total of interest and dividend income, including any amortization and accretion (as applicable) of discounts and premiums, earned from (1) loans and leases whether held-for-sale or held-in-portfolio; (2) investment securities; (3) federal funds sold; (4) securities purchased under agreements to resell; (5) investments in banker's acceptances, commercial paper, or certificates of deposit; (6) dividend income; or (7) other investments not otherwise specified herein.

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