Summary of Significant Accounting Policies - Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	3 Months Ended					6 Months Ended
	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2021	Mar. 31, 2020	Sep. 30, 2018	Jun. 30, 2022	Jun. 30, 2021
Cash Transactions:
Interest paid						$ 45,298	$ 63,683
Income taxes paid, net						70,182	56,073
Operating lease payments						7,669	7,133
Noncash Transactions:
Loans charged-off to the allowance for credit losses	$ 9,173		$ 12,755			15,685	27,029
Loans foreclosed upon and transferred to other real estate owned						0	620
Available-for-sale securities transferred to held-to-maturity portfolio		$ 1,100,000		$ 873,600	$ 179,800	1,059,737	0
Right of use assets recognized during the period in exchange for lease obligations						$ 7,276	$ 4,771