Quarterly Financial Data (Unaudited) - Acquisition and Integration Costs (Details) - USD ($) $ in Thousands		3 Months Ended	12 Months Ended
	Dec. 22, 2017	Dec. 31, 2017	Dec. 31, 2017
Quarterly Financial Data (Unaudited)
Pre-tax acquisition costs			$ 671
Tax Cuts and Jobs Act of 2017 effect on re-measurement of net deferred tax assets	$ 7,103	$ 7,103	7,103
Banking
Quarterly Financial Data (Unaudited)
Pre-tax acquisition costs		$ 671
Tax Cuts and Jobs Act of 2017 effect on re-measurement of net deferred tax assets			$ 6,749