CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Operating Activities:
Net (loss)	$ (185,821)	$ (19,970)
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Depreciation on rental properties	120	119
Realized gain (loss) on sale of available-for-sale MBS	(5,710)	6,147
(Gain) on sale of residential properties	(78)
Amortization of restricted stock	4	25
Net settlements received on interest rate swaps, net of amortization	889	4,861
Loss on interest rate swaps, net	99,609	33,718
(Gain) on derivatives, net of derivative income - TBA Agency MBS	88,791	27,289
Changes in assets and liabilities:
Decrease in reverse repurchase agreements	15,000	20,000
Decrease (increase) in interest receivable	3,954	(765)
Decrease (increase) in prepaid expenses and other	2,206	(4,546)
(Decrease) in accrued interest payable	(322)	(8,705)
Increase in accrued expenses and payables	1,950	2,063
Net cash provided by operating activities	39,797	26,054
Investing Activities:
Proceeds from sales, MBS portfolios	1,170,362	903,822
Purchases, MBS portfolios	(76,283)	(997,367)
Principal payments, MBS portfolios	200,620	185,692
Purchases, Residential mortgage loans held-for-securitization	(4,761)	(18,028)
Principal payments, Residential mortgage loans held-for-securitization	10,049	802
Residential properties purchases	(121)	(195)
Proceeds from sales of residential properties	250
Net cash provided by investing activities	1,300,147	74,756
Financing Activities:
Borrowings from repurchase agreements	6,295,038	7,207,740
Repayments on repurchase agreements	(7,479,777)	(7,258,733)
Borrowings from warehouse line of credit		15,716
Repayments on warehouse line of credit	(17,428)
Net settlements of TBA Agency MBS Contracts	10,002	8,022
Termination of interest rate swaps	(48,037)
Derivative counterparty margin	6,266	5,238
Proceeds from common stock issued	265	356
Preferred Stock dividends paid	(2,297)	(2,297)
Common stock dividends paid	(8,897)	(12,803)
Net cash (used in) financing activities	(1,244,865)	(36,761)
Net increase in cash, cash equivalents, and restricted cash	95,079	64,049
Cash, cash equivalents, and restricted cash at beginning of period	112,935	33,461	$ 33,461
Cash, cash equivalents, and restricted cash at end of period	208,014	97,510	$ 112,935
Supplemental Disclosure of Cash Flow Information:
Cash paid for interest	24,462	31,612
Change in payable for MBS purchased		227,997
Change in payables for residential mortgage loans purchased	(5,545)	100,656
Change in receivable for securities sold	65,828
Residential mortgage loans
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Amortization of premium (discount)	(29)	(29)
Investing Activities:
Principal payments, Residential mortgage loans held-for-investment through consolidated securitization trusts	31	30
Residential loans
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Amortization of premium (discount)	327
Agency MBS
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Amortization of premium (discount)	6,477	5,886
Realized gain (loss) on sale of available-for-sale MBS	(5,710)	6,147
Realized (gain) on sales of Agency MBS held as trading investments	(3,981)	7,363
Unrealized loss (gain) on Agency MBS held as trading investments	1,141	(14,906)
Investing Activities:
Proceeds from sales, MBS portfolios	1,000,000	903,800
Non-Agency MBS
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Amortization of premium (discount)	1,253	1,222
Realized gain (loss) on sale of available-for-sale MBS	55,390
Unrealized loss (gain) on Agency MBS held as trading investments	59,982
Investing Activities:
Proceeds from sales, MBS portfolios	200,000
TBA Agency MBS
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
(Gain) on derivatives, net of derivative income - TBA Agency MBS	$ (12,564)	$ (6,429)