Fair Value Measurements, Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Financial assets
Cash and due from banks	$ 396,761	$ 483,666
Interest-bearing deposits in other financial institutions	71,462	199,702
Federal funds sold and securities purchased under agreements to resell	3,150	32,650
Debt Securities, Held-to-maturity	2,602,247	2,282,853
Investment securities held to maturity, fair value	2,560,943	2,283,574
Investment securities available for sale	4,261,651	4,043,446
FHLB and Federal Reserve Bank stocks	249,040	165,331
Loans, net	22,724,184	20,519,111
Bank and Corporate Owned Life Insurance	659,592	591,057
Derivatives (trading and other assets)	132,919	69,675
Financial liabilities
Short-term funding	256,525	392,282
Other long-term funding	497,619	497,282
Derivatives (trading and other liabilities)	131,612	67,660
Letters of Credit Outstanding, Amount	256,000	235,000
Fair Value, Inputs, Level 1
Financial assets
Cash and due from banks	396,761	483,666
Cash and due from banks, Fair Value	396,761	483,666
Interest-bearing deposits in other financial institutions	71,462	199,702
Interest-bearing deposits in other financial institutions, fair value	71,462	199,702
Federal funds sold and securities purchased under agreements to resell	3,150	32,650
Federal funds sold and securities purchased under agreements to resell, fair value	3,150	32,650
Investment securities available for sale	2,609	2,628
Investment securities available for sale, fair value	2,609	2,628
Fair Value, Inputs, Level 2
Financial assets
Debt Securities, Held-to-maturity	2,602,247	2,282,853
Investment securities held to maturity, fair value	2,560,943	2,283,574
Investment securities available for sale	4,259,042	4,040,818
Investment securities available for sale, fair value	4,259,042	4,040,818
FHLB and Federal Reserve Bank stocks	249,040	165,331
FHLB and Federal Reserve Bank stocks, fair value	249,040	165,331
Loans Receivable Held-for-sale, Net, Not Part of Disposal Group, Mortgage	143,022	85,544
Residential Held-for-sale, Fair Value Disclosure	143,022	85,544
Bank and Corporate Owned Life Insurance	659,592	591,057
Bank owned life insurance, fair value	659,592	591,057
Derivatives (trading and other assets)	136,342	70,850
Derivatives (trading and other assets), fair value	136,342	70,850
Financial liabilities
Brokered CDs and other time deposits	2,727,776	2,349,069
Brokered CDs and other time deposits, fair value	2,727,776	2,349,069
Short-term funding	626,525	676,282
Short-term funding, fair value	626,525	676,282
Other long-term funding	4,925,476	3,397,450
Long-term funding, fair value	4,921,348	3,411,368
Standby letters of credit	2,549	2,402
Standby letters of credit, fair value	2,549	2,402
Derivatives (trading and other liabilities)	132,639	68,835
Derivatives (trading and other liabilities), fair value	132,639	68,835
Fair Value, Inputs, Level 3
Financial assets
Loans, net	22,724,184	20,519,111
Loans, net, fair value	22,282,282	20,314,984
Derivatives (trading and other assets)	3,287	1,538
Derivatives (trading and other assets), fair value	3,287	1,538
Financial liabilities
Noninterest-bearing demand, savings, interest-bearing demand, and money market accounts	21,088,538	20,436,893
Noninterest-bearing demand, savings, interest-bearing demand, and money market deposits, fair value	21,088,538	20,436,893
Derivatives (trading and other liabilities)	919	313
Derivatives (trading and other liabilities), fair value	$ 919	$ 313

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.