Fair Value Measurement - Summary of Financial Assets Measured at Fair Value on Recurring Basis Using Significant Unobservable Inputs (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Investment Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Balance, beginning of period	$ 685	$ 700
Change in fair value	1	(20)
Balance, end of period	686	680
Servicing Assets
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Balance, beginning of period	22,042	19,471
Additions, net	1,603	1,393
Change in fair value	(1,505)	(3,064)
Balance, end of period	$ 22,140	$ 17,800