Aggregate dividends declared during the period for each share of common stock outstanding.

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Amount of cash inflow (outflow) from sales and purchases of trading securities.

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Amount of cash inflow from sale of investment in mortgage-backed security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Subsequent Events - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands		1 Months Ended	3 Months Ended
	Apr. 21, 2020	Apr. 30, 2020	Mar. 31, 2020	Mar. 31, 2019
Subsequent Event [Line Items]
Dividend declared common share, per share				$ 0.13
Proceeds from sales, MBS portfolios			$ 1,170,362	$ 903,822
Non-Agency MBS
Subsequent Event [Line Items]
Proceeds from sales, MBS portfolios			$ 200,000
Subsequent Event
Subsequent Event [Line Items]
Dividend declared common share, per share	$ 0.05
Subsequent Event \| AFS Agency MBS [Member]
Subsequent Event [Line Items]
Proceeds from sales, MBS portfolios		$ 400,000
Subsequent Event \| Non-Agency MBS
Subsequent Event [Line Items]
Proceeds from (Payments for) Trading Securities, Short-term		$ 100,000