Derivative and Hedging Activities, Derivative Instruments Not Designated as Hedging Instruments (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Fair Value, Inputs, Level 3
Derivative Instruments Not Designated as Hedging Instruments [Abstract]
Derivative Asset	$ 972	$ 0
Derivatives (trading liabilities)	0	2,046
Fair Value, Inputs, Level 3 \| Interest Rate Lock Commitments and Forward Commitments Total \| Fair Value, Measurements, Recurring
Derivative Instruments Not Designated as Hedging Instruments [Abstract]
Derivative Asset	6,159	9,624
Fair Value, Inputs, Level 2 \| Interest rate-related instruments — customer and mirror \| Fair Value, Measurements, Recurring
Derivative Instruments Not Designated as Hedging Instruments [Abstract]
Derivative Asset	110,898	192,518
Derivatives (trading liabilities)	24,322	25,680
Fair Value, Inputs, Level 2 \| Interest rate lock commitments (mortgage) \| Fair Value, Measurements, Recurring
Derivative Instruments Not Designated as Hedging Instruments [Abstract]
Derivative Asset	4,637	4,909
Derivatives (trading liabilities)	4,454	4,836
Fair Value, Inputs, Level 2 \| Commodity contracts \| Fair Value, Measurements, Recurring
Derivative Instruments Not Designated as Hedging Instruments [Abstract]
Derivative Asset	6,546	12,486
Derivatives (trading liabilities)	6,471	11,155
Asset
Derivative Instruments Not Designated as Hedging Instruments [Abstract]
Derivatives (trading and other assets), fair value	128,240	219,537
Less: Legally enforceable master netting agreements	3,302	1,936
Less: Cash collateral pledged/received	3,143	10,879
Derivative Asset	121,795	206,722
Liability
Derivative Instruments Not Designated as Hedging Instruments [Abstract]
Derivatives (trading and other liabilities), fair value	35,247	43,716
Less: Legally enforceable master netting agreements	3,302	1,936
Less: Cash collateral pledged/received	18,595	25,625
Derivatives (trading liabilities)	13,351	16,155
Not designated as hedging instruments \| Asset \| Interest rate-related instruments — customer and mirror
Derivative Instruments Not Designated as Hedging Instruments [Abstract]
Notional Amount	3,889,911	3,639,679
Not designated as hedging instruments \| Asset \| Interest rate lock commitments (mortgage)
Derivative Instruments Not Designated as Hedging Instruments [Abstract]
Notional Amount	496,215	411,292
Not designated as hedging instruments \| Asset \| Commodity contracts
Derivative Instruments Not Designated as Hedging Instruments [Abstract]
Notional Amount	16,231	87,547
Not designated as hedging instruments \| Asset \| Mortgage banking(a)(b)
Derivative Instruments Not Designated as Hedging Instruments [Abstract]
Notional Amount	253,663	226,818
Not designated as hedging instruments \| Liability \| Interest rate-related instruments — customer and mirror
Derivative Instruments Not Designated as Hedging Instruments [Abstract]
Notional Amount	3,889,911	3,639,679
Not designated as hedging instruments \| Liability \| Interest rate lock commitments (mortgage)
Derivative Instruments Not Designated as Hedging Instruments [Abstract]
Notional Amount	483,949	398,890
Not designated as hedging instruments \| Liability \| Commodity contracts
Derivative Instruments Not Designated as Hedging Instruments [Abstract]
Notional Amount	16,307	83,214
Not designated as hedging instruments \| Liability \| Mortgage banking(a)(b)
Derivative Instruments Not Designated as Hedging Instruments [Abstract]
Notional Amount	$ 390,000	$ 335,500

Amount of obligation to return cash collateral under master netting arrangements offset against derivative assets.

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