Loans Past Due Status (Details) - USD ($) $ in Thousands		Jun. 30, 2019		Dec. 31, 2018
Summarized details of Loans
Current		$ 23,055,291		$ 22,785,019
Nonaccrual		166,707	[1]	127,901	[2]
Total loans	[3]	23,249,967		22,940,429
Nonaccrual Loans, Current Portion		$ 90,000		$ 74,000
Percent of current nonaccrual loans		54.00%		58.00%
30-59 Days Past Due
Summarized details of Loans
Total Past Due		$ 23,824		$ 21,550
60-89 Days Past Due
Summarized details of Loans
Total Past Due		2,057		3,795
90 Days or More Past Due
Summarized details of Loans
Total Past Due		2,088		2,165
Commercial and industrial
Summarized details of Loans
Current		7,490,030		7,356,187
Nonaccrual		84,151		41,021
Total loans		7,579,384		7,398,044
Commercial and industrial | 30-59 Days Past Due
Summarized details of Loans
Total Past Due		4,769		187
Commercial and industrial | 60-89 Days Past Due
Summarized details of Loans
Total Past Due		139		338
Commercial and industrial | 90 Days or More Past Due
Summarized details of Loans
Total Past Due		293		311
Commercial real estate — owner occupied
Summarized details of Loans
Current		940,222		913,787
Nonaccrual		571		3,957
Total loans		942,811		920,443
Commercial real estate — owner occupied | 30-59 Days Past Due
Summarized details of Loans
Total Past Due		2,018		2,580
Commercial real estate — owner occupied | 60-89 Days Past Due
Summarized details of Loans
Total Past Due		0		119
Commercial real estate — owner occupied | 90 Days or More Past Due
Summarized details of Loans
Total Past Due		0		0
Commercial and business lending
Summarized details of Loans
Current		8,430,252		8,269,974
Nonaccrual		84,722		44,978
Total loans		8,522,194		8,318,487
Commercial and business lending | 30-59 Days Past Due
Summarized details of Loans
Total Past Due		6,787		2,767
Commercial and business lending | 60-89 Days Past Due
Summarized details of Loans
Total Past Due		139		457
Commercial and business lending | 90 Days or More Past Due
Summarized details of Loans
Total Past Due		293		311
Commercial real estate — investor
Summarized details of Loans
Current		3,776,334		3,745,835
Nonaccrual		1,485		1,952
Total loans		3,779,201		3,751,554
Commercial real estate — investor | 30-59 Days Past Due
Summarized details of Loans
Total Past Due		1,382		2,954
Commercial real estate — investor | 60-89 Days Past Due
Summarized details of Loans
Total Past Due		0		813
Commercial real estate — investor | 90 Days or More Past Due
Summarized details of Loans
Total Past Due		0		0
Real estate construction
Summarized details of Loans
Current		1,394,237		1,333,722
Nonaccrual		427		979
Total loans		1,394,815		1,335,031
Real estate construction | 30-59 Days Past Due
Summarized details of Loans
Total Past Due		131		330
Real estate construction | 60-89 Days Past Due
Summarized details of Loans
Total Past Due		19		0
Real estate construction | 90 Days or More Past Due
Summarized details of Loans
Total Past Due		0		0
Commercial real estate lending
Summarized details of Loans
Current		5,170,572		5,079,557
Nonaccrual		1,912		2,931
Total loans		5,174,016		5,086,585
Commercial real estate lending | 30-59 Days Past Due
Summarized details of Loans
Total Past Due		1,513		3,284
Commercial real estate lending | 60-89 Days Past Due
Summarized details of Loans
Total Past Due		19		813
Commercial real estate lending | 90 Days or More Past Due
Summarized details of Loans
Total Past Due		0		0
Total commercial
Summarized details of Loans
Current		13,600,824		13,349,531
Nonaccrual		86,634		47,909
Total loans		13,696,210		13,405,072
Total commercial | 30-59 Days Past Due
Summarized details of Loans
Total Past Due		8,300		6,051
Total commercial | 60-89 Days Past Due
Summarized details of Loans
Total Past Due		159		1,270
Total commercial | 90 Days or More Past Due
Summarized details of Loans
Total Past Due		293		311
Residential mortgage
Summarized details of Loans
Current		8,199,557		8,200,432
Nonaccrual		68,166		67,574
Total loans		8,277,479		8,277,712
Residential mortgage | 30-59 Days Past Due
Summarized details of Loans
Total Past Due		9,199		9,272
Residential mortgage | 60-89 Days Past Due
Summarized details of Loans
Total Past Due		558		434
Residential mortgage | 90 Days or More Past Due
Summarized details of Loans
Total Past Due		0		0
Home equity
Summarized details of Loans
Current		898,550		876,085
Nonaccrual		11,835		12,339
Total loans		916,213		894,473
Home equity | 30-59 Days Past Due
Summarized details of Loans
Total Past Due		5,176		4,826
Home equity | 60-89 Days Past Due
Summarized details of Loans
Total Past Due		652		1,223
Home equity | 90 Days or More Past Due
Summarized details of Loans
Total Past Due		0		0
Other consumer
Summarized details of Loans
Current		356,360		358,970
Nonaccrual		72		79
Total loans		360,065		363,171
Other consumer | 30-59 Days Past Due
Summarized details of Loans
Total Past Due		1,150		1,401
Other consumer | 60-89 Days Past Due
Summarized details of Loans
Total Past Due		688		868
Other consumer | 90 Days or More Past Due
Summarized details of Loans
Total Past Due		1,795		1,853
Total consumer
Summarized details of Loans
Current		9,454,467		9,435,487
Nonaccrual		80,073		79,992
Total loans		9,553,757		9,535,357
Total consumer | 30-59 Days Past Due
Summarized details of Loans
Total Past Due		15,524		15,499
Total consumer | 60-89 Days Past Due
Summarized details of Loans
Total Past Due		1,898		2,525
Total consumer | 90 Days or More Past Due
Summarized details of Loans
Total Past Due		$ 1,795		$ 1,853

[1]
(a) Of the total nonaccrual loans, $90 million, or 54%, were current with respect to payment at June 30, 2019

[2] (a) Of the total nonaccrual loans, $74 million, or 58%, were current with respect to payment at December 31, 2018.

[3] (a) Includes $2 million and $5 million of purchased credit-impaired loans at June 30, 2019 and December 31, 2018, respectively.