Derivative and Hedging Activities, Derivative Instruments Not Designated as Hedging Instruments (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Not Designated as Hedging Instrument | Trading assets | Interest rate-related instruments — customer and mirror
Derivative Instruments Not Designated as Hedging Instruments [Abstract]
Notional Amount	$ 2,668,542	$ 2,183,687
Derivative, Fair Value, Net	62,708	28,494
Not Designated as Hedging Instrument | Trading assets | Foreign currency exchange forwards
Derivative Instruments Not Designated as Hedging Instruments [Abstract]
Notional Amount	143,551	124,851
Derivative, Fair Value, Net	3,317	2,495
Not Designated as Hedging Instrument | Trading assets | Commodity contracts
Derivative Instruments Not Designated as Hedging Instruments [Abstract]
Notional Amount	419,459	457,868
Derivative, Fair Value, Net	66,894	38,686
Not Designated as Hedging Instrument | Trading liabilities | Interest rate-related instruments — customer and mirror
Derivative Instruments Not Designated as Hedging Instruments [Abstract]
Notional Amount	2,668,542	2,183,687
Derivative, Fair Value, Net	(62,141)	(28,035)
Not Designated as Hedging Instrument | Trading liabilities | Foreign currency exchange forwards
Derivative Instruments Not Designated as Hedging Instruments [Abstract]
Notional Amount	136,177	118,094
Derivative, Fair Value, Net	(3,091)	(2,339)
Not Designated as Hedging Instrument | Trading liabilities | Commodity contracts
Derivative Instruments Not Designated as Hedging Instruments [Abstract]
Notional Amount	419,458	457,108
Derivative, Fair Value, Net	(66,380)	(37,286)
Not Designated as Hedging Instrument | Other assets | Interest rate lock commitments (mortgage)
Derivative Instruments Not Designated as Hedging Instruments [Abstract]
Notional Amount	335,070	222,736
Derivative, Fair Value, Net	3,287	1,538
Not Designated as Hedging Instrument | Other assets | Purchased options (time deposit)
Derivative Instruments Not Designated as Hedging Instruments [Abstract]
Notional Amount	25,511	31,063
Derivative, Fair Value, Net	1,027	1,175
Not Designated as Hedging Instrument | Other liabilities | Forward commitments (mortgage)
Derivative Instruments Not Designated as Hedging Instruments [Abstract]
Notional Amount	312,003	164,567
Derivative, Fair Value, Net	(919)	(313)
Not Designated as Hedging Instrument | Other liabilities | Written options (time deposit)
Derivative Instruments Not Designated as Hedging Instruments [Abstract]
Notional Amount	25,511	31,063
Derivative, Fair Value, Net	(1,027)	(1,175)
Designated as Hedging Instrument | Other assets | interest rate product [Member]
Derivative Instruments Not Designated as Hedging Instruments [Abstract]
Notional Amount	500,000	0
Derivative, Fair Value, Net	$ 2,396	$ 0