Basis of Presentation and Significant Accounting Policies - Summary of Supplemental Cash Flow Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash payments:
Interest	$ 127,713	$ 91,813	$ 56,682
Income taxes (net of refunds)	5,494	(2,505)	4,326
Noncash Investing and Financing Activities:
Securities transferred from held-to-maturity to available-for-sale	381,992	447,026
Securities transferred from available-for-sale to held-to-maturity		323,990
Transfer of premises and equipment to assets held for sale	2,689	$ 9,634	$ 16,617
Operating lease right-of-use assets obtained in exchange for lease obligations	113,498
Finance lease right-of-use assets obtained in exchange for lease obligations	$ 7,871