Loans and Allowance for Credit Losses (Schedule of Financing Receivables Past Due) (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Not Past Due	$ 22,733,209	$ 22,359,032
Loans and Leases Receivable, Net of Deferred Income	23,834,889	23,154,988
Financing Receivable, before Allowance for Credit Loss and Fee	23,834,889	23,154,988
Financing Receivable, 90 Days or More Past Due, Still Accruing	673,000	531,000
1-4 single family residential
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Not Past Due	4,679,984	4,887,618
Financing Receivable, Originated in Current Fiscal Year	255,615	820,613
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	820,369	615,021
Financing Receivable, Originated Two Years before Latest Fiscal Year	494,020	835,512
Financing Receivable, Originated Three Years before Latest Fiscal Year	755,863	792,223
Financing Receivable, Originated Four Years before Latest Fiscal Year	784,899	644,937
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	1,633,100	1,245,630
Financing Receivable, before Allowance for Credit Loss and Fee	4,743,866	4,953,936
US Government Agency Insured Loans [Member]
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Not Past Due	51,276	93,560
Financing Receivable, before Allowance for Credit Loss and Fee	826,238	698,644
Home equity loans and lines of credit
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Not Past Due	1,478	1,320
Financing Receivable, before Allowance for Credit Loss and Fee	1,547	1,320
Other Consumer Loans
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Not Past Due	6,156	7,219
Financing Receivable, before Allowance for Credit Loss and Fee	6,156	7,219
Multi-family
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Not Past Due	1,858,695	2,217,705
Financing Receivable, Originated in Current Fiscal Year	42,877
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	324,882
Financing Receivable, Originated Two Years before Latest Fiscal Year	205,994
Financing Receivable, Originated Three Years before Latest Fiscal Year	233,038
Financing Receivable, Originated Four Years before Latest Fiscal Year	363,983
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	683,372
Financing Receivable, before Allowance for Credit Loss and Fee	1,893,753	2,217,705
Commercial real estate, Non-owner occupied
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Not Past Due	4,859,344	5,015,458
Financing Receivable, Originated in Current Fiscal Year	243,019
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	1,281,855
Financing Receivable, Originated Two Years before Latest Fiscal Year	838,565
Financing Receivable, Originated Three Years before Latest Fiscal Year	557,813
Financing Receivable, Originated Four Years before Latest Fiscal Year	857,879
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	1,053,628
Financing Receivable, before Allowance for Credit Loss and Fee	4,940,531	5,030,904
Construction and land
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Not Past Due	246,263	240,647
Financing Receivable, Originated in Current Fiscal Year	7,208
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	126,822
Financing Receivable, Originated Two Years before Latest Fiscal Year	17,472
Financing Receivable, Originated Three Years before Latest Fiscal Year	58,624
Financing Receivable, Originated Four Years before Latest Fiscal Year	34,977
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	1,263
Financing Receivable, before Allowance for Credit Loss and Fee	246,609	243,925
Commercial real estate, Owner occupied
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Not Past Due	2,020,077	2,041,352
Financing Receivable, Originated in Current Fiscal Year	131,430
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	338,623
Financing Receivable, Originated Two Years before Latest Fiscal Year	309,415
Financing Receivable, Originated Three Years before Latest Fiscal Year	336,572
Financing Receivable, Originated Four Years before Latest Fiscal Year	355,669
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	518,722
Financing Receivable, before Allowance for Credit Loss and Fee	2,041,346	2,062,808
Commercial and industrial
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Not Past Due	4,593,422	4,595,847
Financing Receivable, Originated in Current Fiscal Year	357,260
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	1,069,143
Financing Receivable, Originated Two Years before Latest Fiscal Year	422,233
Financing Receivable, Originated Three Years before Latest Fiscal Year	331,293
Financing Receivable, Originated Four Years before Latest Fiscal Year	251,505
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	124,773
Financing Receivable, before Allowance for Credit Loss and Fee	4,691,326	4,655,349
Payment Protection Plan [Member]
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Not Past Due	827,359
Financing Receivable, Originated in Current Fiscal Year	827,359
Financing Receivable, before Allowance for Credit Loss and Fee	827,359
Pinnacle Public Finance [Member]
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Not Past Due	1,242,506	1,202,430
Financing Receivable, Originated in Current Fiscal Year	125,882
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	134,838
Financing Receivable, Originated Two Years before Latest Fiscal Year	92,537
Financing Receivable, Originated Three Years before Latest Fiscal Year	232,269
Financing Receivable, Originated Four Years before Latest Fiscal Year	227,317
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	429,663
Financing Receivable, before Allowance for Credit Loss and Fee	1,242,506	1,202,430
Bridge - franchise finance [Member]
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Not Past Due	596,136	610,315
Financing Receivable, Originated in Current Fiscal Year	85,164
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	267,338
Financing Receivable, Originated Two Years before Latest Fiscal Year	146,547
Financing Receivable, Originated Three Years before Latest Fiscal Year	55,570
Financing Receivable, Originated Four Years before Latest Fiscal Year	44,438
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	24,082
Financing Receivable, before Allowance for Credit Loss and Fee	623,139	627,482
Bridge - equipment finance [Member]
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Not Past Due	589,785	677,089
Financing Receivable, Originated in Current Fiscal Year	24,349
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	203,469
Financing Receivable, Originated Two Years before Latest Fiscal Year	117,072
Financing Receivable, Originated Three Years before Latest Fiscal Year	121,717
Financing Receivable, Originated Four Years before Latest Fiscal Year	55,549
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	67,629
Financing Receivable, before Allowance for Credit Loss and Fee	589,785	684,794
Mortgage warehouse lending [Member]
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, Not Past Due	1,160,728	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	1,160,728	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	249,912	804,913
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	807,365	609,814
Financing Receivable, Originated Two Years before Latest Fiscal Year	488,280	830,710
Financing Receivable, Originated Three Years before Latest Fiscal Year	753,109	783,318
Financing Receivable, Originated Four Years before Latest Fiscal Year	776,895	633,833
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	1,604,423	1,225,030
Financing Receivable, before Allowance for Credit Loss and Fee	4,679,984	4,887,618
30 - 59 Days Past Due
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss and Fee	206,281	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	5,703	13,915
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	11,477	3,003
Financing Receivable, Originated Two Years before Latest Fiscal Year	3,372	3,751
Financing Receivable, Originated Three Years before Latest Fiscal Year	2,701	8,419
Financing Receivable, Originated Four Years before Latest Fiscal Year	7,417	4,308
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	18,605	12,238
Financing Receivable, before Allowance for Credit Loss and Fee	49,275	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	53,017	45,347
30 - 59 Days Past Due | Home equity loans and lines of credit
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss and Fee	69	0
30 - 59 Days Past Due | Other Consumer Loans
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss and Fee	0	0
30 - 59 Days Past Due | Multi-family
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss and Fee	29,047	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	52,937	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	1,081	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	20,855	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	0	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	96,045	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	720	442
Financing Receivable, Originated Two Years before Latest Fiscal Year	75	137
Financing Receivable, Originated Three Years before Latest Fiscal Year	53	486
Financing Receivable, Originated Four Years before Latest Fiscal Year	103	1,766
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	1,882	4,962
Financing Receivable, before Allowance for Credit Loss and Fee	2,833	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	52,620	30,426
60 - 89 Days Past Due | Home equity loans and lines of credit
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss and Fee	0	0
60 - 89 Days Past Due | Other Consumer Loans
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss and Fee	0	0
60 - 89 Days Past Due | Multi-family
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss and Fee	6,011	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	7,979	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	3,376	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	22,601	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	625	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	799,354	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	2,293	914
Financing Receivable, Originated Three Years before Latest Fiscal Year	0	0
Financing Receivable, Originated Four Years before Latest Fiscal Year	484	5,030
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	8,190	3,400
Financing Receivable, before Allowance for Credit Loss and Fee	11,774	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	669,325	529,311
Financing Receivable, 90 Days or More Past Due, Still Accruing		529,000
90 Days or More Past Due | Home equity loans and lines of credit
Financing Receivable Investment Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss and Fee	0	0
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	20,271	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	16,812	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	54,448	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	26,378	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	$ 37,300	$ 36,300