Segment Reporting (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Segment Reporting Information [Line Items]
Interest Income (Expense), Net	$ 329,893	$ 327,630	$ 297,737
(Recovery of) provision for credit losses	(11,916)	12,054	6,171
Other Income (Loss) and Security Gains	129,944	125,664	97,193
Total other expense	283,518	286,595	263,988
Income before income taxes	188,235	154,645	124,771
Income taxes	34,290	26,722	22,071
Net Income (Loss) Attributable to Parent	153,945	127,923	102,700
Assets, Total	9,560,254	9,279,021	8,558,377
Total loans	6,871,122	7,177,785	6,501,404
Total deposits	7,904,528	7,572,358	7,052,612
Depreciation, Amortization and Accretion, Net	13,267	10,814	9,112
Other Noninterest Expense	270,251	275,781	254,876
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Interest Income (Expense), Net	1,250	1,250	1,250
Income taxes	0	0	0
Assets, Total	(1,413)	(1,028)	(18,910)
Total deposits	(254,060)	(250,965)	(76,418)
Depreciation, Amortization and Accretion, Net	0	0	0
Other Noninterest Expense	0	0	0
Operating Segments
Segment Reporting Information [Line Items]
Interest Income (Expense), Net	328,398	326,375	293,130
Income taxes	37,615	27,125	26,133
Assets, Total	9,538,217	9,236,915	8,521,537
Total deposits	8,157,720	7,820,983	7,125,111
Depreciation, Amortization and Accretion, Net	13,265	10,803	9,089
Other Noninterest Expense	253,413	258,135	228,344
Corporate, Non-Segment
Segment Reporting Information [Line Items]
Interest Income (Expense), Net	245	5	3,357
Income taxes	(3,325)	(403)	(4,062)
Assets, Total	23,450	43,134	55,750
Total deposits	868	2,340	3,919
Depreciation, Amortization and Accretion, Net	2	11	23
Other Noninterest Expense	16,838	17,646	26,532
Pnb Segment [Member]
Segment Reporting Information [Line Items]
Interest Income (Expense), Net	328,398	326,375	293,130
(Recovery of) provision for credit losses	(8,554)	30,813	8,356
Other Income (Loss) and Security Gains	126,802	124,231	92,392
Total other expense	266,678	268,938	237,433
Income before income taxes	197,076	150,855	139,733
Income taxes	37,615	27,125	26,133
Net Income (Loss) Attributable to Parent	159,461	123,730	113,600
Assets, Total	9,538,217	9,236,915	8,521,537
Total loans	6,868,935	7,165,840	6,481,644
Total deposits	8,157,720	7,820,983	7,125,111
Other Segments [Member]
Segment Reporting Information [Line Items]
Interest Income (Expense), Net	1,495	1,255	4,607
(Recovery of) provision for credit losses	(3,362)	(18,759)	(2,185)
Other Income (Loss) and Security Gains	3,142	1,433	4,801
Total other expense	16,840	17,657	26,555
Income before income taxes	(8,841)	3,790	(14,962)
Income taxes	(3,325)	(403)	(4,062)
Net Income (Loss) Attributable to Parent	(5,516)	4,193	(10,900)
Assets, Total	22,037	42,106	36,840
Total loans	2,187	11,945	19,760
Total deposits	$ (253,192)	$ (248,625)	$ (72,499)