Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance	$ 288,735	$ 224,127	$ 153,942
Net change in unrealized gain	3,001	(14,824)	6,280
Reclassification of net loss realized and included in earnings	458		8
Accumulated other comprehensive loss before income tax	(13,082)	(20,906)	(2,980)
Income tax provision (benefit)	1,109	(4,365)	2,039
Balance	304,913	288,735	224,127
Accumulated Other Comprehensive Loss
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance	(16,541)	(5,019)	(9,268)
Balance	(14,191)	(16,541)	(5,019)
Available-For-Sale Securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance	(13,360)	(5,019)	(9,268)
Net change in unrealized gain	12,072	(10,466)	6,280
Reclassification of net loss realized and included in earnings	458		8
Accumulated other comprehensive loss before income tax	(830)	(16,548)	(2,980)
Income tax provision (benefit)	3,558	(3,188)	2,039
Balance	(4,388)	(13,360)	(5,019)
Cash Flow Hedges
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance	(3,181)	0	0
Net change in unrealized gain	(9,071)	(4,358)	0
Reclassification of net loss realized and included in earnings	0		0
Accumulated other comprehensive loss before income tax	(12,252)	(4,358)	0
Income tax provision (benefit)	(2,449)	(1,177)	0
Balance	$ (9,803)	(3,181)	$ 0
Accounting Standards Update 2018-02
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Reclassification of net loss realized and included in earnings		(1,063)
Accounting Standards Update 2018-02 | Available-For-Sale Securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Reclassification of net loss realized and included in earnings		(1,063)
Accounting Standards Update 2018-02 | Cash Flow Hedges
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Reclassification of net loss realized and included in earnings		$ 0