Loans and Allowance for Credit Losses (Schedule of Financing Receivables Past Due) (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Not Past Due	$ 22,673,241	$ 22,359,032
Loans and Leases Receivable, Net of Deferred Income	23,779,315	23,154,988
Financing Receivable, before Allowance for Credit Loss and Fee	23,779,315	23,154,988
Financing Receivable, 90 Days or More Past Due, Still Accruing	595,000	531,000
1-4 single family residential
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Not Past Due	4,790,941	4,887,618
Financing Receivable, Originated in Current Fiscal Year	536,862	820,613
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	749,121	615,021
Financing Receivable, Originated Two Years before Latest Fiscal Year	434,232	835,512
Financing Receivable, Originated Three Years before Latest Fiscal Year	701,527	792,223
Financing Receivable, Originated Four Years before Latest Fiscal Year	836,015	644,937
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	1,587,399	1,245,630
Financing Receivable, before Allowance for Credit Loss and Fee	4,845,156	4,953,936
US Government Agency Insured Loans [Member]
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Not Past Due	382,620	93,560
Financing Receivable, before Allowance for Credit Loss and Fee	1,089,055	698,644
Other Consumer Loans
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Not Past Due	6,434	8,539
Financing Receivable, before Allowance for Credit Loss and Fee	6,689	8,539
Multi-family
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Not Past Due	1,778,604	2,217,705
Financing Receivable, Originated in Current Fiscal Year	184,395
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	301,618
Financing Receivable, Originated Two Years before Latest Fiscal Year	173,147
Financing Receivable, Originated Three Years before Latest Fiscal Year	234,826
Financing Receivable, Originated Four Years before Latest Fiscal Year	328,230
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	550,502
Financing Receivable, before Allowance for Credit Loss and Fee	1,810,126	2,217,705
Commercial real estate, Non-owner occupied
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Not Past Due	4,709,649	5,015,458
Financing Receivable, Originated in Current Fiscal Year	307,866
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	1,278,470
Financing Receivable, Originated Two Years before Latest Fiscal Year	826,844
Financing Receivable, Originated Three Years before Latest Fiscal Year	542,006
Financing Receivable, Originated Four Years before Latest Fiscal Year	841,980
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	1,009,982
Financing Receivable, before Allowance for Credit Loss and Fee	4,910,835	5,030,904
Construction and land
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Not Past Due	263,035	240,647
Financing Receivable, Originated in Current Fiscal Year	20,155
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	131,579
Financing Receivable, Originated Two Years before Latest Fiscal Year	17,061
Financing Receivable, Originated Three Years before Latest Fiscal Year	57,625
Financing Receivable, Originated Four Years before Latest Fiscal Year	35,461
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	1,259
Financing Receivable, before Allowance for Credit Loss and Fee	263,381	243,925
Commercial real estate, Owner occupied
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Not Past Due	2,036,782	2,041,352
Financing Receivable, Originated in Current Fiscal Year	199,895
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	336,795
Financing Receivable, Originated Two Years before Latest Fiscal Year	294,882
Financing Receivable, Originated Three Years before Latest Fiscal Year	328,930
Financing Receivable, Originated Four Years before Latest Fiscal Year	351,185
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	493,682
Financing Receivable, before Allowance for Credit Loss and Fee	2,051,577	2,062,808
Commercial and industrial
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Not Past Due	4,358,670	4,595,847
Financing Receivable, Originated in Current Fiscal Year	397,105
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	1,053,543
Financing Receivable, Originated Two Years before Latest Fiscal Year	400,613
Financing Receivable, Originated Three Years before Latest Fiscal Year	289,221
Financing Receivable, Originated Four Years before Latest Fiscal Year	247,244
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	88,935
Financing Receivable, before Allowance for Credit Loss and Fee	4,427,351	4,655,349
Payment Protection Plan [Member]
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Not Past Due	829,798
Financing Receivable, Originated in Current Fiscal Year	829,798
Financing Receivable, before Allowance for Credit Loss and Fee	829,798
Pinnacle Public Finance [Member]
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Not Past Due	1,157,706	1,202,430
Financing Receivable, Originated in Current Fiscal Year	141,475
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	120,453
Financing Receivable, Originated Two Years before Latest Fiscal Year	74,711
Financing Receivable, Originated Three Years before Latest Fiscal Year	214,037
Financing Receivable, Originated Four Years before Latest Fiscal Year	212,343
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	394,687
Financing Receivable, before Allowance for Credit Loss and Fee	1,157,706	1,202,430
Bridge - franchise finance [Member]
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Not Past Due	577,583	610,315
Financing Receivable, Originated in Current Fiscal Year	87,733
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	263,187
Financing Receivable, Originated Two Years before Latest Fiscal Year	139,420
Financing Receivable, Originated Three Years before Latest Fiscal Year	51,614
Financing Receivable, Originated Four Years before Latest Fiscal Year	42,466
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	21,802
Financing Receivable, before Allowance for Credit Loss and Fee	606,222	627,482
Bridge - equipment finance [Member]
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Not Past Due	530,516	677,089
Financing Receivable, Originated in Current Fiscal Year	24,073
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	191,044
Financing Receivable, Originated Two Years before Latest Fiscal Year	106,252
Financing Receivable, Originated Three Years before Latest Fiscal Year	108,701
Financing Receivable, Originated Four Years before Latest Fiscal Year	42,307
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	58,139
Financing Receivable, before Allowance for Credit Loss and Fee	530,516	684,794
Mortgage warehouse lending [Member]
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Not Past Due	1,250,903	768,472
Financing Receivable, Originated in Current Fiscal Year	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	0
Financing Receivable, Originated Two Years before Latest Fiscal Year	0
Financing Receivable, Originated Three Years before Latest Fiscal Year	0
Financing Receivable, Originated Four Years before Latest Fiscal Year	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	0
Financing Receivable, before Allowance for Credit Loss and Fee	1,250,903	768,472
Financial Asset, Current [Member] | 1-4 single family residential
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Originated in Current Fiscal Year	528,199	804,913
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	741,476	609,814
Financing Receivable, Originated Two Years before Latest Fiscal Year	426,780	830,710
Financing Receivable, Originated Three Years before Latest Fiscal Year	699,906	783,318
Financing Receivable, Originated Four Years before Latest Fiscal Year	833,132	633,833
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	1,561,448	1,225,030
Financing Receivable, before Allowance for Credit Loss and Fee	4,790,941	4,887,618
30 - 59 Days Past Due
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss and Fee	215,468	108,571
30 - 59 Days Past Due | 1-4 single family residential
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Originated in Current Fiscal Year	8,663	13,915
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	6,838	3,003
Financing Receivable, Originated Two Years before Latest Fiscal Year	5,691	3,751
Financing Receivable, Originated Three Years before Latest Fiscal Year	1,568	8,419
Financing Receivable, Originated Four Years before Latest Fiscal Year	1,855	4,308
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	17,284	12,238
Financing Receivable, before Allowance for Credit Loss and Fee	41,899	45,634
30 - 59 Days Past Due | US Government Agency Insured Loans [Member]
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss and Fee	70,183	45,347
30 - 59 Days Past Due | Other Consumer Loans
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss and Fee	233	0
30 - 59 Days Past Due | Multi-family
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss and Fee	23,152	0
30 - 59 Days Past Due | Commercial real estate, Non-owner occupied
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss and Fee	51,512	0
30 - 59 Days Past Due | Construction and land
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss and Fee	0	2,396
30 - 59 Days Past Due | Commercial real estate, Owner occupied
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss and Fee	630	1,336
30 - 59 Days Past Due | Commercial and industrial
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss and Fee	27,840	2,313
30 - 59 Days Past Due | Payment Protection Plan [Member]
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss and Fee	0
30 - 59 Days Past Due | Pinnacle Public Finance [Member]
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss and Fee	0	0
30 - 59 Days Past Due | Bridge - franchise finance [Member]
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss and Fee	19	3,840
30 - 59 Days Past Due | Bridge - equipment finance [Member]
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss and Fee	0	7,705
30 - 59 Days Past Due | Mortgage warehouse lending [Member]
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss and Fee	0	0
60 - 89 Days Past Due
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss and Fee	206,119	52,154
60 - 89 Days Past Due | 1-4 single family residential
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0	1,785
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	0	442
Financing Receivable, Originated Two Years before Latest Fiscal Year	0	137
Financing Receivable, Originated Three Years before Latest Fiscal Year	0	486
Financing Receivable, Originated Four Years before Latest Fiscal Year	24	1,766
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	2,256	4,962
Financing Receivable, before Allowance for Credit Loss and Fee	2,280	9,578
60 - 89 Days Past Due | US Government Agency Insured Loans [Member]
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss and Fee	45,355	30,426
60 - 89 Days Past Due | Other Consumer Loans
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss and Fee	22	0
60 - 89 Days Past Due | Multi-family
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss and Fee	8,370	0
60 - 89 Days Past Due | Commercial real estate, Non-owner occupied
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss and Fee	130,454	928
60 - 89 Days Past Due | Construction and land
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss and Fee	0	0
60 - 89 Days Past Due | Commercial real estate, Owner occupied
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss and Fee	1,706	4,420
60 - 89 Days Past Due | Commercial and industrial
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss and Fee	4,891	4,301
60 - 89 Days Past Due | Payment Protection Plan [Member]
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss and Fee	0
60 - 89 Days Past Due | Pinnacle Public Finance [Member]
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss and Fee	0	0
60 - 89 Days Past Due | Bridge - franchise finance [Member]
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss and Fee	13,041	2,501
60 - 89 Days Past Due | Bridge - equipment finance [Member]
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss and Fee	0	0
60 - 89 Days Past Due | Mortgage warehouse lending [Member]
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss and Fee	0	0
90 Days or More Past Due
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss and Fee	684,487	635,231
90 Days or More Past Due | 1-4 single family residential
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	807	1,762
Financing Receivable, Originated Two Years before Latest Fiscal Year	1,761	914
Financing Receivable, Originated Three Years before Latest Fiscal Year	53	0
Financing Receivable, Originated Four Years before Latest Fiscal Year	1,004	5,030
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	6,411	3,400
Financing Receivable, before Allowance for Credit Loss and Fee	10,036	11,106
90 Days or More Past Due | US Government Agency Insured Loans [Member]
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss and Fee	590,897	529,311
90 Days or More Past Due | Other Consumer Loans
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss and Fee	0	0
90 Days or More Past Due | Multi-family
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss and Fee	0	0
90 Days or More Past Due | Commercial real estate, Non-owner occupied
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss and Fee	19,220	14,518
90 Days or More Past Due | Construction and land
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss and Fee	346	882
90 Days or More Past Due | Commercial real estate, Owner occupied
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss and Fee	12,459	15,700
90 Days or More Past Due | Commercial and industrial
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss and Fee	35,950	52,888
90 Days or More Past Due | Payment Protection Plan [Member]
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss and Fee	0
90 Days or More Past Due | Pinnacle Public Finance [Member]
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss and Fee	0	0
90 Days or More Past Due | Bridge - franchise finance [Member]
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss and Fee	15,579	10,826
90 Days or More Past Due | Bridge - equipment finance [Member]
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss and Fee	0	0
90 Days or More Past Due | Mortgage warehouse lending [Member]
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss and Fee	0	0
Small business finance [Member]
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, 90 Days or More Past Due, Still Accruing	$ 33,600	$ 36,300