Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Accumulated Other Comprehensive Income
Balance, beginning	$ 40,226	$ (9,427)
Other comprehensive income (loss) before reclassification	60,142	33,312
Reclassification adjustments for (gains) losses included in net income	(644)	2
Total other comprehensive income, net of tax	59,498	33,314
Balance, end	99,724	23,887
Available-For-Sale Debt Securities
Accumulated Other Comprehensive Income
Balance, beginning	40,226	(6,613)
Other comprehensive income (loss) before reclassification	60,142	34,681
Reclassification adjustments for (gains) losses included in net income	(644)	(165)
Total other comprehensive income, net of tax	59,498	34,516
Balance, end	99,724	27,903
Derivatives Used for Cash Flow Hedges
Accumulated Other Comprehensive Income
Balance, beginning	0	(2,814)
Other comprehensive income (loss) before reclassification	0	(1,369)
Reclassification adjustments for (gains) losses included in net income	0	167
Total other comprehensive income, net of tax	0	(1,202)
Balance, end	$ 0	$ (4,016)