Derivative Instruments and Balance Sheet Offsetting (Net Gains (Losses) Recorded in Other Comprehensive Income and the Income Statement) (Details) - Designated as hedging - Interest rate swaps - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Derivative [Line Items]
Amount of gain recognized in other comprehensive income	$ 2,841	$ 4,263
Amount of gain (loss) reclassified from other comprehensive income to interest income or expense	$ 1,871	$ (1,633)