Deposits - Summary of Deposit Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Interest and Noninterest Bearing Domestic Deposit Liabilities To Deposit Liabilities [Abstract]
Noninterest-bearing demand	$ 1,631,942	$ 1,510,224
Interest-bearing checking	2,092,022	2,057,052
Money market	1,327,612	1,225,890
Savings	630,280	584,361
Certificates of deposit $250 thousand and under	794,283	895,056
Certificates of deposit over $250 thousand	159,087	183,200
Deposits	$ 6,635,226	$ 6,455,783
Percentage Of Interest and Noninterest Bearing Domestic Deposit Liabilities To Deposit Liabilities [Abstract]
Noninterest-bearing demand	24.60%	23.40%
Interest-bearing checking	31.50%	31.90%
Money market	20.00%	19.00%
Savings	9.50%	9.10%
Certificates of deposit $250 thousand and under	12.00%	13.80%
Certificates of deposit over $250 thousand	2.40%	2.80%
Total deposits	100.00%	100.00%