Accumulated Other Comprehensive Loss ("AOCL"), Reclassification Out of Each Components (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Reclassifications out of AOCL [Abstract]
Total reclassifications before tax	$ 11,548	$ 11,199
Interest expense	(6,393)	(2,861)
Income tax expense	2,167	2,038
Reclassifications, net of tax	9,381	9,161
Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassifications out of AOCL [Abstract]
Reclassifications, net of tax	226	(10)
Unrealized Losses on Securities Available For Sale [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassifications out of AOCL [Abstract]
Net gains (losses) on securities	137	(19)
Net impairment loss recognized in earnings	0	0
Total reclassifications before tax	137	(19)
Income tax expense	29	(4)
Reclassifications, net of tax	108	(15)
Unrealized Gains (Losses) on Cash Flow Hedges [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassifications out of AOCL [Abstract]
Interest expense	(149)	(6)
Income tax expense	(31)	(1)
Reclassifications, net of tax	$ (118)	$ (5)