Fair Value Measurements - Amount of Net Gains (Losses) from Fair Value Changes (Detail) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019
Fair Value Disclosures [Abstract]
Mortgage loans held for sale, at fair value	$ 711	$ 652
Mortgage loans held for investment, at fair value	$ 0	$ 191

Net Gains Losses From Change In Fair Value Of Mortgages Loans Held For Investment

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