Deposits - Certificates of deposits and Scheduled maturities of time deposits - (Details) - USD ($)	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016
Deposits Disclosure Abstract
Aggregate amounts of certificates of deposits in denominations of $250,000 or more	$ 187,500,000	$ 83,700,000	$ 90,800,000
Increased insurance limit on deposit accounts	250,000
Traditional, out-of-market brokered deposits	$ 23,900,000	$ 2,900,000	$ 2,900,000