Accumulated Other Comprehensive Loss ("AOCL"), Reclassification Out of Each Components (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Reclassifications out of AOCL [Abstract]
Total reclassifications before tax	$ 13,417	$ 10,884	$ 24,965	$ 22,083
Interest expense	(6,817)	(4,123)	(13,210)	(6,984)
Income tax expense	2,687	2,067	4,854	4,105
Reclassifications, net of tax	10,730	8,817	20,111	17,978
Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassifications out of AOCL [Abstract]
Reclassifications, net of tax	112	21	338	11
Unrealized Gains (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	0	(26)	137	(45)
Net impairment loss recognized in earnings	0	0	0	0
Total reclassifications before tax	0	(26)	137	(45)
Income tax expense	0	(5)	29	(9)
Reclassifications, net of tax	0	(21)	108	(36)
Unrealized Gains (Losses) on Cash Flow Hedges [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassifications out of AOCL [Abstract]
Interest expense	(142)	(53)	(291)	(59)
Income tax expense	(30)	(11)	(61)	(12)
Reclassifications, net of tax	$ (112)	$ (42)	$ (230)	$ (47)