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SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - ASU 2016-13 (Detail) - USD ($) $ in Thousands	Mar. 31, 2020	Jan. 01, 2020	Dec. 31, 2019	Mar. 31, 2019	Dec. 31, 2018
New Accounting Pronouncements
Allowance for risk-sharing obligations	$ 64,110		$ 11,471	$ 6,682	$ 4,622
Retained earnings	$ 801,139		$ 796,775
ASU 2016-13 \| Restatement Adjustment
New Accounting Pronouncements
Allowance for risk-sharing obligations		$ 31,600
Retained earnings		(23,700)
Deferred tax assets		$ 7,900