CONSOLIDATED STATEMENTS OF INCOME (Unaudited) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Interest expense related to derivatives reclassified from accumulated other comprehensive income	$ 3,596	$ 3,656
Net security gains reclassified from accumulated other comprehensive income	1,441	2,482
Income tax expense reclassified from accumulated other comprehensive income	5,123	5,530
Reclassification out of Accumulated Other Comprehensive Income | Accumulated Net Gain (Loss) from Derivatives
Interest expense related to derivatives reclassified from accumulated other comprehensive income	197	397
Reclassification out of Accumulated Other Comprehensive Income | Accumulated Net Unrealized Investment Gain (Loss)
Net security gains reclassified from accumulated other comprehensive income	1,441	2,482
Reclassification out of Accumulated Other Comprehensive Income | Accumulated Other Comprehensive Income (Loss)
Income tax expense reclassified from accumulated other comprehensive income	$ 261	$ 778