Loans And Allowance For Credit Losses (Credit Quality Indicators Commercial Loan Portfolio) (Details) - Commercial Portfolio Segment [Member] - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Credit Quality Indicator [Line Items]
Current Fiscal Year	$ 699,098	$ 2,917,439
Fiscal Year before Current Fiscal Year	2,620,807	1,869,035
Two Years before Current Fiscal Year	1,687,861	1,223,303
Three Years before Current Fiscal Year	1,132,435	555,494
Four Years before Current Fiscal Year	499,550	408,432
Prior	891,764	593,927
Revolving Loans Amortized Cost Basis	2,231,072	1,913,008
Total	9,762,587	9,480,638
Business
Credit Quality Indicator [Line Items]
Current Fiscal Year	310,669	1,476,920
Fiscal Year before Current Fiscal Year	1,248,812	705,474
Two Years before Current Fiscal Year	645,619	581,191
Three Years before Current Fiscal Year	541,949	267,274
Four Years before Current Fiscal Year	236,764	160,729
Prior	392,162	289,793
Revolving Loans Amortized Cost Basis	2,132,533	1,822,154
Total	5,508,508	5,303,535
Real estate - construction and land
Credit Quality Indicator [Line Items]
Current Fiscal Year	155,429	643,868
Fiscal Year before Current Fiscal Year	626,603	358,127
Two Years before Current Fiscal Year	261,482	66,985
Three Years before Current Fiscal Year	53,869	17,991
Four Years before Current Fiscal Year	17,103	15,813
Prior	15,957	2,252
Revolving Loans Amortized Cost Basis	13,968	13,230
Total	1,144,411	1,118,266
Real estate - business
Credit Quality Indicator [Line Items]
Current Fiscal Year	233,000	796,651
Fiscal Year before Current Fiscal Year	745,392	805,434
Two Years before Current Fiscal Year	780,760	575,127
Three Years before Current Fiscal Year	536,617	270,229
Four Years before Current Fiscal Year	245,683	231,890
Prior	483,645	301,882
Revolving Loans Amortized Cost Basis	84,571	77,624
Total	3,109,668	3,058,837
Pass [Member]
Credit Quality Indicator [Line Items]
Current Fiscal Year	693,148	2,848,164
Fiscal Year before Current Fiscal Year	2,564,429	1,762,837
Two Years before Current Fiscal Year	1,582,241	1,173,441
Three Years before Current Fiscal Year	1,101,960	480,987
Four Years before Current Fiscal Year	426,880	332,781
Prior	749,654	527,195
Revolving Loans Amortized Cost Basis	2,204,029	1,884,944
Total	9,322,341	9,010,349
Pass [Member] | Business
Credit Quality Indicator [Line Items]
Current Fiscal Year	305,308	1,473,869
Fiscal Year before Current Fiscal Year	1,246,520	704,157
Two Years before Current Fiscal Year	644,426	554,759
Three Years before Current Fiscal Year	533,462	248,739
Four Years before Current Fiscal Year	219,320	159,238
Prior	368,615	270,454
Revolving Loans Amortized Cost Basis	2,106,483	1,795,073
Total	5,424,134	5,206,289
Pass [Member] | Real estate - construction and land
Credit Quality Indicator [Line Items]
Current Fiscal Year	155,429	598,734
Fiscal Year before Current Fiscal Year	591,643	346,507
Two Years before Current Fiscal Year	249,882	66,985
Three Years before Current Fiscal Year	53,869	2,110
Four Years before Current Fiscal Year	1,236	2,655
Prior	2,800	2,252
Revolving Loans Amortized Cost Basis	13,968	13,230
Total	1,068,827	1,032,473
Pass [Member] | Real estate - business
Credit Quality Indicator [Line Items]
Current Fiscal Year	232,411	775,561
Fiscal Year before Current Fiscal Year	726,266	712,173
Two Years before Current Fiscal Year	687,933	551,697
Three Years before Current Fiscal Year	514,629	230,138
Four Years before Current Fiscal Year	206,324	170,888
Prior	378,239	254,489
Revolving Loans Amortized Cost Basis	83,578	76,641
Total	2,829,380	2,771,587
Special Mention [Member]
Credit Quality Indicator [Line Items]
Current Fiscal Year	2,622	50,445
Fiscal Year before Current Fiscal Year	23,987	30,448
Two Years before Current Fiscal Year	30,740	28,076
Three Years before Current Fiscal Year	10,310	50,611
Four Years before Current Fiscal Year	46,747	3,558
Prior	10,483	5,335
Revolving Loans Amortized Cost Basis	2,806	16,546
Total	127,695	185,019
Special Mention [Member] | Business
Credit Quality Indicator [Line Items]
Current Fiscal Year	2,622	1,785
Fiscal Year before Current Fiscal Year	976	126
Two Years before Current Fiscal Year	83	17,576
Three Years before Current Fiscal Year	1,315	12,050
Four Years before Current Fiscal Year	11,452	1,490
Prior	8,138	3,232
Revolving Loans Amortized Cost Basis	2,806	16,545
Total	27,392	52,804
Special Mention [Member] | Real estate - construction and land
Credit Quality Indicator [Line Items]
Current Fiscal Year	0	44,649
Fiscal Year before Current Fiscal Year	19,474	0
Two Years before Current Fiscal Year	0	0
Three Years before Current Fiscal Year	0	985
Four Years before Current Fiscal Year	976	0
Prior	0	0
Revolving Loans Amortized Cost Basis	0	0
Total	20,450	45,634
Special Mention [Member] | Real estate - business
Credit Quality Indicator [Line Items]
Current Fiscal Year	0	4,011
Fiscal Year before Current Fiscal Year	3,537	30,322
Two Years before Current Fiscal Year	30,657	10,500
Three Years before Current Fiscal Year	8,995	37,576
Four Years before Current Fiscal Year	34,319	2,068
Prior	2,345	2,103
Revolving Loans Amortized Cost Basis	0	1
Total	79,853	86,581
Substandard [Member]
Credit Quality Indicator [Line Items]
Current Fiscal Year	3,026	18,400
Fiscal Year before Current Fiscal Year	32,305	75,750
Two Years before Current Fiscal Year	74,880	21,785
Three Years before Current Fiscal Year	20,165	22,158
Four Years before Current Fiscal Year	24,288	72,093
Prior	126,704	56,040
Revolving Loans Amortized Cost Basis	24,237	11,518
Total	305,605	277,744
Substandard [Member] | Business
Credit Quality Indicator [Line Items]
Current Fiscal Year	2,437	836
Fiscal Year before Current Fiscal Year	1,230	1,191
Two Years before Current Fiscal Year	1,110	8,855
Three Years before Current Fiscal Year	7,172	4,936
Four Years before Current Fiscal Year	4,530	1
Prior	10,503	10,775
Revolving Loans Amortized Cost Basis	23,244	10,536
Total	50,226	37,130
Substandard [Member] | Real estate - construction and land
Credit Quality Indicator [Line Items]
Current Fiscal Year	0	485
Fiscal Year before Current Fiscal Year	15,486	11,620
Two Years before Current Fiscal Year	11,600	0
Three Years before Current Fiscal Year	0	14,896
Four Years before Current Fiscal Year	14,891	13,158
Prior	13,157	0
Revolving Loans Amortized Cost Basis	0	0
Total	55,134	40,159
Substandard [Member] | Real estate - business
Credit Quality Indicator [Line Items]
Current Fiscal Year	589	17,079
Fiscal Year before Current Fiscal Year	15,589	62,939
Two Years before Current Fiscal Year	62,170	12,930
Three Years before Current Fiscal Year	12,993	2,326
Four Years before Current Fiscal Year	4,867	58,934
Prior	103,044	45,265
Revolving Loans Amortized Cost Basis	993	982
Total	200,245	200,455
Non-Accrual [Member]
Credit Quality Indicator [Line Items]
Current Fiscal Year	302	430
Fiscal Year before Current Fiscal Year	86	0
Two Years before Current Fiscal Year	0	1
Three Years before Current Fiscal Year	0	1,738
Four Years before Current Fiscal Year	1,635	0
Prior	4,923	5,357
Revolving Loans Amortized Cost Basis	0	0
Total	6,946	7,526
Non-Accrual [Member] | Business
Credit Quality Indicator [Line Items]
Current Fiscal Year	302	430
Fiscal Year before Current Fiscal Year	86	0
Two Years before Current Fiscal Year	0	1
Three Years before Current Fiscal Year	0	1,549
Four Years before Current Fiscal Year	1,462	0
Prior	4,906	5,332
Revolving Loans Amortized Cost Basis	0	0
Total	6,756	7,312
Non-Accrual [Member] | Real estate - business
Credit Quality Indicator [Line Items]
Current Fiscal Year	0	0
Fiscal Year before Current Fiscal Year	0	0
Two Years before Current Fiscal Year	0	0
Three Years before Current Fiscal Year	0	189
Four Years before Current Fiscal Year	173	0
Prior	17	25
Revolving Loans Amortized Cost Basis	0	0
Total	$ 190	$ 214