Deposits (Details) - USD ($) $ in Thousands		Dec. 31, 2019	Dec. 31, 2018
Deposits [Abstract]
Demand and other noninterest-bearing		$ 5,328,146	$ 5,227,216
Money market	[1]	2,322,644	2,294,125
Interest-bearing demand	[1]	1,150,437	1,084,863
Savings	[1]	882,050	889,849
Interest-bearing public funds, other than certificates of deposit	[1]	301,203	233,938
Certificates of deposit less than $250,000		218,764	243,849
Certificates of deposit greater than $250,000		151,995	89,473
Certificates of deposit insured by CDARS®		17,065	23,580
Brokered certificates of deposit		12,259	57,930
Reciprocal money market accounts		300,158	313,692
Subtotal		10,684,721	10,458,515
Deposits, Valuation Adjustment From Acquisition Accounting		(13)	(389)
Total deposits		10,684,708	10,458,126
Deposit Liabilities Reclassified as Loans Receivable		3,800	$ 4,000
Time Deposits, Fiscal Year Maturity [Abstract]
2020		313,241
2021		53,679
2022		19,346
2023		8,060
2024		5,593
Thereafter		151
Total		$ 400,070

[1] Beginning in 2019, interest-bearing public funds, other than certificates of deposit, are presented separately in this table. Prior period amounts have been reclassified to conform to current period presentation.