Commitments and Contingent Liabilities (Details)	12 Months Ended
	Dec. 31, 2018 USD ($) shares	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
Other Commitments [Abstract]
The Net Asset Value of Units in Mutual Funds (per unit)	1.00
Minimum Average Cash Balance Required to be Maintained at Federal Reserve by Subsidiary Bank	$ 1,200,000,000	$ 1,900,000,000
Operating Leases, Rent Expense, Net [Abstract]
Operating Leases, Rent Expense, Net	28,500,000	$ 27,500,000	$ 25,800,000
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
Operating Leases, Future Minimum Payments, Due in 2019	25,800,000
Operating Leases, Future Minimum Payments, Due in 2020	24,800,000
Operating Leases, Future Minimum Payments, Due in 2021	21,300,000
Operating Leases, Future Minimum Payments, Due in 2022	15,200,000
Operating Leases, Future Minimum Payments, Due in 2023	13,000,000.0
Operating Leases, Future Minimum Payments, Due Thereafter	$ 78,600,000
Visa Membership [Member]
Loss Contingencies [Line Items]
Number of Visa Class B Shares Owned by Entity (in shares) | shares	252,233
Number of Visa Class A Shares Visa Class B Shares Are Convertible To (in shares) | shares	411,089
Misuse of Revenues Pledged to Municipal Bonds [Member] | Judicial Ruling [Member]
Litigation Settlement [Abstract]
Outstanding principal, accrued interest and other amounts required by bond documents	$ 40,000,000
Disgorged fees	1,067,721
Litigation Settlement, Expense	$ 600,000
Misuse of Revenues Pledged to Municipal Bonds [Member] | Pending Litigation [Member]
Litigation Settlement [Abstract]
Loss Contingency, Number of Plaintiffs	2
Alleged total of judgment against nursing home operator	$ 8,000,000
Bank Participation in Fraudulent Sale of Securities by Principals [Member] | Pending Litigation [Member]
Litigation Settlement [Abstract]
Loss Contingency, Number of Plaintiffs	19
Purchase of facilities from principals subject to SEC New Jersey proceedings [Member] | Pending Litigation [Member]
Litigation Settlement [Abstract]
Outstanding principal, accrued interest and other amounts required by bond documents	$ 60,000,000
Number of individuals who purchased facilities from the principals subject to SEC New Jersey proceedings	2
Number of principals in SEC New Jersey proceedings	2