CONSOLIDATED STATEMENTS OF INCOME (Unaudited) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Interest benefit	$ (3,102)	$ (3,430)	$ (9,378)	$ (10,514)
Gain (loss) on securities	1,535	1,300	4,347	4,964
Income tax expense (benefit)	13,250	13,681	45,064	27,007
Reclassification out of accumulated other comprehensive income (loss) | Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent
Interest benefit	543	595	1,601	1,195
Reclassification out of accumulated other comprehensive income (loss) | Accumulated Net Unrealized Investment Gain (Loss)
Gain (loss) on securities	1,535	1,099	4,347	4,763
Reclassification out of accumulated other comprehensive income (loss) | Accumulated Other Comprehensive Income (Loss)
Income tax expense (benefit)	$ 524	$ 429	$ 1,501	$ 1,509