Financial Instruments with Off-Balance-Sheet Risk - Schedule of Financial Instruments Outstanding Contract Amounts Represent Credit Risk (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments to fund loans and leases	$ 261,902	$ 345,608
Unfunded commitments to fund mortgage warehouse loans	1,378,364	1,537,900
Unfunded commitments under lines of credit and credit cards	1,065,474	867,131
Letters of credit	48,856	55,659
Other unused commitments	$ 2,736	$ 4,822