Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Statement of Comprehensive Income [Abstract]
Net (loss) income	$ (4,926)	$ 24,971	$ 30,245	$ 65,124
Other comprehensive income
Unrealized (loss) gain on debt securities (net of tax benefit of $105 and tax expense of $604 in 2020, and net of tax expense of $55 and $489 in 2019, respectively)	(461)	164	1,644	1,723
Accretion of unrealized loss on debt securities reclassified to held-to-maturity (net of tax expense of $75 and $235 in 2020, and net of tax expense of $86 and $257 in 2019, respectively)	108	124	336	372
Reclassification adjustment for gains included in net income (net of tax expense of $45 and $45 in 2020 and $0 in 2019)	168	0	168	0
Other comprehensive income, net of tax	(185)	288	2,148	2,095
Total comprehensive (loss) income	(5,111)	25,259	32,393	67,219
Dividends on preferred shares	1,093	0	1,093	0
Comprehensive (loss) income available to common stockholders	$ (6,204)	$ 25,259	$ 31,300	$ 67,219