Derivatives - Schedule of Derivative Financial Instruments (Details) - USD ($)	Dec. 31, 2018	Dec. 31, 2017	Jul. 31, 2017
Derivatives, Fair Value [Line Items]
Notional Amount			$ 100,000,000
Asset	$ 14,316,000	$ 9,690,000
Liability	11,637,000	1,699,000
Not designated as hedging:
Derivatives, Fair Value [Line Items]
Notional Amount	1,258,047,000	1,810,484,000
Asset	13,595,000	8,258,000
Liability	11,637,000	1,699,000
Designated as hedging:
Derivatives, Fair Value [Line Items]
Notional Amount	30,000,000	130,000,000
Asset	721,000	1,432,000
Liability	0	0
Interest rate contracts | Not designated as hedging:
Derivatives, Fair Value [Line Items]
Notional Amount	295,333,000	146,754,000
Asset	6,679,000	1,146,000
Liability	6,679,000	1,146,000
Forward commitments | Not designated as hedging:
Derivatives, Fair Value [Line Items]
Notional Amount	474,208,000	870,574,000
Asset	0	0
Liability	4,958,000	553,000
Interest rate-lock commitments | Not designated as hedging:
Derivatives, Fair Value [Line Items]
Notional Amount	318,706,000	504,156,000
Asset	6,241,000	6,768,000
Liability	0	0
Futures contracts | Not designated as hedging:
Derivatives, Fair Value [Line Items]
Notional Amount	166,000,000	283,000,000
Asset	649,000	315,000
Liability	0	0
Option contracts | Not designated as hedging:
Derivatives, Fair Value [Line Items]
Notional Amount	3,800,000	6,000,000
Asset	26,000	29,000
Liability	0	0
Interest rate swaps | Designated as hedging:
Derivatives, Fair Value [Line Items]
Notional Amount	30,000,000	130,000,000
Asset	721,000	1,432,000
Liability	$ 0	$ 0