Business Segment Information - Banking Segment (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Segment Reporting Information [Line Items]
Total interest income	$ 82,364	$ 79,415	$ 232,176	$ 229,982
Total interest expense	7,985	14,650	31,046	40,487
Net interest income (expense)	74,379	64,765	201,130	189,495
Credit loss expense (benefit)	(258)	2,865	33,649	7,560
Net interest income after credit loss expense	74,637	61,900	167,481	181,935
Gain on sale of subsidiary or division	0	0	9,758	0
Other noninterest income	10,493		28,241
Noninterest income	10,493	7,742	37,999	22,903
Noninterest expense	55,297	52,153	162,776	151,423
Net income before income tax expense	29,833	17,489	42,704	53,415
Total assets	5,836,787		5,836,787		$ 5,060,297
Gross loans	4,852,911		4,852,911		4,194,512
Operating Segments | Banking
Segment Reporting Information [Line Items]
Total interest income	52,288	54,266	157,957	155,645
Total interest expense	6,176	13,091	25,368	35,746
Net interest income (expense)	49,424	44,093	141,462	128,087
Credit loss expense (benefit)	(3,417)	2,019	27,378	5,847
Net interest income after credit loss expense	52,841	42,074	114,084	122,240
Gain on sale of subsidiary or division			9,758
Other noninterest income	7,490		22,586
Noninterest income		6,401		19,150
Noninterest expense	40,584	38,371	122,001	109,406
Net income before income tax expense	19,747	10,104	24,427	31,984
Total assets	5,767,857		5,767,857		4,976,009
Gross loans	4,759,135		4,759,135		4,108,735
Operating Segments | Factoring
Segment Reporting Information [Line Items]
Total interest income	30,068	24,869	73,952	73,435
Total interest expense	0	0	0	0
Net interest income (expense)	26,756	21,951	65,079	65,247
Credit loss expense (benefit)	3,053	846	4,437	1,789
Net interest income after credit loss expense	23,703	21,105	60,642	63,458
Gain on sale of subsidiary or division			0
Other noninterest income	3,157		5,524
Noninterest income		1,291		3,572
Noninterest expense	13,665	12,792	37,695	39,340
Net income before income tax expense	13,195	9,604	28,471	27,690
Total assets	1,042,571		1,042,571		662,002
Gross loans	948,987		948,987		573,372
Operating Segments | Corporate
Segment Reporting Information [Line Items]
Total interest income	8	280	267	902
Total interest expense	1,809	1,559	5,678	4,741
Net interest income (expense)	(1,801)	(1,279)	(5,411)	(3,839)
Credit loss expense (benefit)	106	0	1,834	(76)
Net interest income after credit loss expense	(1,907)	(1,279)	(7,245)	(3,763)
Gain on sale of subsidiary or division			0
Other noninterest income	(154)		131
Noninterest income		50		181
Noninterest expense	1,048	990	3,080	2,677
Net income before income tax expense	(3,109)	(2,219)	(10,194)	(6,259)
Total assets	828,065		828,065		771,048
Gross loans	800		800		1,519
Eliminations
Segment Reporting Information [Line Items]
Total assets	(1,801,706)		(1,801,706)		(1,348,762)
Gross loans	(856,011)		(856,011)		$ (489,114)
Eliminations | Banking
Segment Reporting Information [Line Items]
Intersegment interest allocations	3,312	2,918	8,873	8,188
Eliminations | Factoring
Segment Reporting Information [Line Items]
Intersegment interest allocations	(3,312)	(2,918)	(8,873)	(8,188)
Eliminations | Corporate
Segment Reporting Information [Line Items]
Intersegment interest allocations	$ 0	$ 0	$ 0	$ 0