Fair Value Measurements, Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Financial assets
Cash and due from banks	$ 406,994	$ 416,154
Interest-bearing deposits in other financial institutions	1,340,385	298,759
Federal funds sold and securities purchased under agreements to resell	25,000	1,135
Available-for-sale Securities	3,323,346	3,085,441
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	1,799,893	1,879,005
Investment securities held to maturity, fair value	1,930,541	2,028,943
Equity securities with readily determinable fair values, Fair Value	3,000	2,000
Equity Securities without Readily Determinable Fair Value, Amount	14,000	13,000
Investment securities gains (losses), net	17,144	15,106
FHLB and Federal Reserve Bank stocks	168,281	168,280
Residential loans held for sale	160,547	129,158
Loans, net	23,628,725	24,068,022
Bank owned life insurance, fair value	682,709	679,647
Financial liabilities
Short-term funding	226,205	252,317
FHLB advances	1,619,826	1,632,723
Letters of Credit Outstanding, Amount	251,000	279,000
Other long-term funding	2,168,851	2,182,188
US Treasury Securities
Financial assets
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	1,000	999
Investment securities held to maturity, fair value	1,013	1,024
Other Liabilities [Member]
Financial liabilities
Derivatives (trading liabilities)	36,494
Derivatives (trading and other liabilities), fair value	36,494
Fair Value, Inputs, Level 1
Financial assets
Available-for-sale Securities	124,533	26,531
Investment securities available for sale, fair value	124,533	26,531
Equity securities with readily determinable fair value, Carrying Amount	3,187	1,661
Equity securities with readily determinable fair values, Fair Value	3,187	1,661
Fair Value, Inputs, Level 1 \| Fair Value, Measurements, Recurring \| US Treasury Securities
Financial assets
Available-for-sale Securities	124,533	26,531
Fair Value, Inputs, Level 2
Financial assets
Available-for-sale Securities	3,198,813	3,058,910
Investment securities available for sale, fair value	3,198,813	3,058,910
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	1,798,835	1,877,939
Investment securities held to maturity, fair value	1,929,470	2,027,852
Financial liabilities
Brokered CDs and other time deposits	1,472,395	1,757,030
Brokered CDs and other time deposits, fair value	1,475,846	1,766,200
Short-term funding	226,205	252,317
Short-term funding, fair value	226,200	252,303
Long-term funding, fair value	570,836	578,233
Advances, Fair Value Disclosure	1,693,728	1,760,727
Standby letters of credit	2,549	2,731
Standby letters of credit, fair value	2,549	2,731
Other long-term funding	549,024	549,465
Fair Value, Inputs, Level 2 \| Fair Value, Measurements, Recurring \| US Treasury Securities
Financial assets
Available-for-sale Securities		26,531
Fair Value, Inputs, Level 2 \| Other Assets [Member]
Financial assets
Derivative Asset	139,219	209,913
Derivatives (trading and other assets), fair value	139,219	209,913
Fair Value, Inputs, Level 2 \| Other Liabilities [Member]
Financial liabilities
Derivatives (trading liabilities)	36,065	41,671
Derivatives (trading and other liabilities), fair value	36,065	41,671
Fair Value, Inputs, Level 3
Financial assets
Equity Securities without Readily Determinable Fair Value, Amount	13,958	13,444
Investment securities gains (losses), net	13,958	13,444
Loans, net, fair value	23,601,959	24,012,738
Financial liabilities
Noninterest-bearing demand, savings, interest-bearing demand, and money market accounts	25,791,904	24,725,451
Noninterest-bearing demand, savings, interest-bearing demand, and money market deposits, fair value	25,791,904	24,725,451
Derivatives (trading liabilities)	430	2,046
Fair Value, Inputs, Level 3 \| Mortgage banking(a) \| Fair Value, Measurements, Recurring
Financial assets
Derivative Asset	$ 6,543	$ 9,624

This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents Available-for-sale Securities which consist of all investments in certain debt and equity securities neither classified as trading or held-to-maturity securities. A debt security represents a creditor relationship with an enterprise. Debt securities include, among other items, US Treasury securities, US government securities, municipal securities, corporate bonds, convertible debt, commercial paper, and all securitized debt instruments. An equity security represents an ownership interest in an enterprise or the right to acquire or dispose of an ownership interest in an enterprise at fixed or determinable prices. Equity securities include, among other things, common stock, certain preferred stock, warrant rights, call options, and put options, but do not include convertible debt. An entity may opt to provide the reader with additional narrative text to better understand the nature of investments in debt and equity securities which are categorized as Available-for-sale.

No definition available.