Derivative Financial Instruments - Schedule of Notional Amount and Fair Value Derivative Financial Instruments (Detail) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Derivative [Line Items]
Asset derivatives, notional amount	$ 952,357	$ 144,512
Liability derivatives, notional amount	515,725	356,243
Asset derivatives not designated as hedging instruments	29,578	4,527
Liability derivatives designated as hedging instruments	10,083	2,394
Liability derivatives not designated as hedging instruments	14,307	3,065
Designated as Hedging Instrument [Member]
Derivative [Line Items]
Liability derivatives, notional amount	329,225	82,243
Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Asset derivatives, notional amount	952,357	144,512
Liability derivatives, notional amount	186,500	274,000
Liability derivatives not designated as hedging instruments	4,224	671
Fair Value Hedging [Member]
Derivative [Line Items]
Liability derivatives designated as hedging instruments	8,424	2,394
Fair Value Hedging [Member] | Designated as Hedging Instrument [Member]
Derivative [Line Items]
Liability derivatives, notional amount	79,225	82,243
Cash Flow Hedging [Member]
Derivative [Line Items]
Liability derivatives designated as hedging instruments	1,659	0
Cash Flow Hedging [Member] | Designated as Hedging Instrument [Member]
Derivative [Line Items]
Liability derivatives, notional amount	250,000	0
Other Assets [Member]
Derivative [Line Items]
Asset derivatives not designated as hedging instruments	1,745	9
Other Assets [Member] | Interest Rate Lock Commitments [Member]
Derivative [Line Items]
Asset derivatives not designated as hedging instruments	27,833	4,518
Other Assets [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Lock Commitments [Member]
Derivative [Line Items]
Asset derivatives, notional amount	878,925	117,252
Other Liabilities [Member] | TBA Mortgage Backed Securities [Member]
Derivative [Line Items]
Liability derivatives not designated as hedging instruments	4,224	671
Other Liabilities [Member] | Not Designated as Hedging Instrument [Member] | TBA Mortgage Backed Securities [Member]
Derivative [Line Items]
Liability derivatives, notional amount	186,500	274,000
Interest Rate Contracts [Member] | Other Liabilities [Member] | Fair Value Hedging [Member] | Hedged Commercial Loans [Member]
Derivative [Line Items]
Liability derivatives designated as hedging instruments	8,424	2,394
Interest Rate Contracts [Member] | Other Liabilities [Member] | Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Hedged Commercial Loans [Member]
Derivative [Line Items]
Liability derivatives, notional amount	79,225	82,243
Interest Rate Contracts [Member] | Other Liabilities [Member] | Cash Flow Hedging [Member] | Designated as Hedging Instrument [Member] | Hedged Commercial Loans Federal Home Loan Bank [Member]
Derivative [Line Items]
Liability derivatives, notional amount	250,000	0
Liability derivatives designated as hedging instruments	1,659	0
Forward Loan Sale Commitments [Member] | Other Assets [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Asset derivatives, notional amount	$ 73,432	$ 27,260