Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance, beginning	$ 40,226
Total other comprehensive income (loss), net of tax	102,864	$ 49,653	$ (7,448)
Balance, end	143,090	40,226
Available-For-Sale Debt Securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance, beginning	40,226	(6,613)	5,031
Other comprehensive income (loss) before reclassification	104,067	57,607	(11,653)
Reclassification adjustments for (gains) losses included in net income	(850)	(10,768)	9
Total other comprehensive income (loss), net of tax	103,217	46,839	(11,644)
Balance, end	143,443	40,226	(6,613)
Derivatives Used for Cash Flow Hedges
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance, beginning	0	(2,814)	(7,010)
Other comprehensive income (loss) before reclassification	(353)	(5,261)	2,453
Reclassification adjustments for (gains) losses included in net income	0	8,075	1,743
Total other comprehensive income (loss), net of tax	(353)	2,814	4,196
Balance, end	(353)	0	(2,814)
Accumulated Other Comprehensive Income (Loss)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance, beginning	40,226	(9,427)	(1,979)
Other comprehensive income (loss) before reclassification	103,714	52,346	(9,200)
Reclassification adjustments for (gains) losses included in net income	(850)	(2,693)	1,752
Total other comprehensive income (loss), net of tax	102,864	49,653	(7,448)
Balance, end	$ 143,090	$ 40,226	$ (9,427)