Deposits (Details) - USD ($) $ in Thousands		Dec. 31, 2017	Dec. 31, 2016
Deposits by Type [Line Items]
Noninterest-bearing Domestic Deposit, Demand		$ 2,025,690	$ 1,753,648
Deposits, Savings and NOW	[1]	716,296	652,819
Deposits, Money Market Deposits	[1]	3,121,811	3,102,048
Time Deposits, Less than $100,000	[1]	250,070	236,001
Time deposits $100,000 to less than $250,000	[1]	82,665	100,570
Time Deposits, at or Above FDIC Insurance Limit		313,714	240,060
Deposits		$ 6,510,246	$ 6,085,146

[1] Includes brokered deposits.