Segment Reporting - Key Operating Results of Business Segments (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Segment Reporting Information [Line Items]
Interest income	$ 61,691	$ 62,614	$ 185,961	$ 186,466
Interest expense	10,074	19,482	41,029	60,400
Net interest income	51,617	43,132	144,932	126,066
Provision for loan losses	1,548	172	6,979	1,943
Noninterest income	23,641	13,982	43,285	31,578
Noninterest expense	30,595	32,694	94,404	97,921
Income before taxes on income	43,115	24,248	86,834	57,780
Operating Segments | Banking
Segment Reporting Information [Line Items]
Interest income	61,691	62,614	185,961	186,466
Interest expense	10,024	19,328	40,899	60,132
Net interest income	51,667	43,286	145,062	126,334
Provision for loan losses	1,548	172	6,979	1,943
Noninterest income	17,976	8,173	26,270	14,638
Noninterest expense	24,949	26,397	76,235	78,785
Income before taxes on income	43,146	24,890	88,118	60,244
Operating Segments | Wealth Management
Segment Reporting Information [Line Items]
Noninterest income	6,020	6,161	18,139	17,874
Noninterest expense	5,166	5,423	16,735	16,508
Income before taxes on income	854	738	1,404	1,366
Other.
Segment Reporting Information [Line Items]
Interest expense	50	154	130	268
Net interest income	(50)	(154)	(130)	(268)
Noninterest income	(355)	(352)	(1,124)	(934)
Noninterest expense	480	874	1,434	2,628
Income before taxes on income	$ (885)	$ (1,380)	$ (2,688)	$ (3,830)