Derivative and Hedging Activities, Derivative Instruments Not Designated as Hedging Instruments (Details) - Not Designated as Hedging Instrument - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Trading assets | Interest rate-related instruments — customer and mirror
Derivative Instruments Not Designated as Hedging Instruments [Abstract]
Notional Amount	$ 2,118,409	$ 2,039,323
Fair Value	28,105	33,671
Trading assets | Foreign currency exchange forwards
Derivative Instruments Not Designated as Hedging Instruments [Abstract]
Notional Amount	93,300	109,675
Fair Value	1,480	2,002
Trading assets | Commodity contracts
Derivative Instruments Not Designated as Hedging Instruments [Abstract]
Notional Amount	304,554	127,582
Fair Value	18,991	16,725
Trading liabilities | Interest rate-related instruments — customer and mirror
Derivative Instruments Not Designated as Hedging Instruments [Abstract]
Notional Amount	2,118,409	2,039,323
Fair Value	(27,691)	(33,188)
Trading liabilities | Foreign currency exchange forwards
Derivative Instruments Not Designated as Hedging Instruments [Abstract]
Notional Amount	92,969	106,251
Fair Value	(1,412)	(1,943)
Trading liabilities | Commodity contracts
Derivative Instruments Not Designated as Hedging Instruments [Abstract]
Notional Amount	303,790	128,368
Fair Value	(18,040)	(15,972)
Other assets | Interest rate lock commitments (mortgage)
Derivative Instruments Not Designated as Hedging Instruments [Abstract]
Notional Amount	356,798	285,345
Fair Value	2,680	206
Other assets | Forward commitments (mortgage)
Derivative Instruments Not Designated as Hedging Instruments [Abstract]
Notional Amount	151,500	179,600
Fair Value	159	2,908
Other assets | Purchased options (time deposit)
Derivative Instruments Not Designated as Hedging Instruments [Abstract]
Notional Amount	75,899	80,554
Fair Value	1,531	2,576
Other liabilities | Written options (time deposit)
Derivative Instruments Not Designated as Hedging Instruments [Abstract]
Notional Amount	75,899	80,554
Fair Value	$ (1,531)	$ (2,576)