Securities - Unrealized Gains (Losses) of Debt Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Total unrealized gains (losses) on debt securities available-for-sale, Gross Unrealized Losses	$ 3,070	$ 5,645
Total unrealized gains (losses) on debt securities available-for-sale, Gross Unrealized Losses	(10,867)	(3,967)
Total unrealized gains (losses) on debt securities available-for-sale, Net Unrealized Gains/(Losses)	(7,797)	1,678
Accumulated Other Comprehensive Income (Loss), Debt Securities Available For Sale Gross Unrealized Gain Adjustment, Tax Expense (Benefit)	(652)	(1,982)
Accumulated Other Comprehensive Income (Loss), Debt Securities Available For Sale Gross Unrealized Loss Adjustment, Tax Expense (Benefit)	2,308	1,393
Accumulated Other Comprehensive Income (Loss), Debt Securities Available-for-sale Adjustment, Tax Expense (Benefit)	1,656	(589)
Accumulated Other Comprehensive Income (Loss), Debt Securities Available For Sale Gross Unrealized Gain Adjustment Net Of Tax	2,418	3,663
Accumulated Other Comprehensive Income (Loss), Debt Securities Available For Sale Gross Unrealized Losses Adjustment Net Of Tax	(8,559)	(2,574)
Accumulated Other Comprehensive Income (Loss), Debt Securities Available-for-sale Securities Adjustment, Net of Tax	$ (6,141)	$ 1,089