Other Comprehensive Income (Loss) (Narrative) (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Class of Stock [Line Items]
Accumulated other comprehensive income (loss)	$ (107,777)	$ (54,754)
Net unrealized gains (losses) on cash flow hedges | Valuation Allowance of Deferred Tax Assets
Class of Stock [Line Items]
Accumulated other comprehensive income (loss)	(12,100)
Net unrealized gains (losses) on investment securities available for sale | Valuation Allowance of Deferred Tax Assets
Class of Stock [Line Items]
Accumulated other comprehensive income (loss)	$ (13,300)