Accumulated Other Comprehensive Loss ("AOCL"), Reclassification Out of Each components (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total reclassifications before tax	$ 10,018	$ 9,352	$ 27,207	$ 24,458
Interest expense	(2,459)	(1,747)	(6,413)	(4,975)
Income tax expense	3,159	2,979	8,443	7,547
Reclassifications, net of tax	6,859	6,373	18,764	16,911
Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassifications, net of tax	2		78
Unrealized Gains on Securities Available For Sale [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net gains on securities	8	15	125	298
Net impairment loss recognized in earnings	0	0	0	0
Total reclassifications before tax	8	15	125	298
Income tax expense	3	5	44	104
Reclassifications, net of tax	5	$ 10	81	$ 194
Unrealized Gains on Cash Flow Hedges [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest expense	(5)		(5)
Income tax expense	(2)		(2)
Reclassifications, net of tax	$ (3)		$ (3)