Derivatives and Hedging Activities - Schedule of Notional Amounts of Outstanding Derivative Positions (Details) - USD ($)		9 Months Ended
	Sep. 06, 2017	Sep. 30, 2017	Dec. 31, 2016	Sep. 22, 2015
Derivative [Line Items]
Derivative Asset, Notional Amount		$ 510,832,000	$ 253,851,000
Derivative Asset, Estimated Fair Value		10,721,000	2,749,000
Notional amount of terminated commitment		327,569,000	153,593,000	$ 100,000,000
Derivative Liabilities, Estimated Fair Value		$ 9,099,000	1,314,000
Interest rate swap designated as a cash flow hedge, inception date		Sep. 22, 2015
Interest rate swap designated as a cash flow hedge, fixed interest rate				1.94%
Interest rate swap contracts
Derivative [Line Items]
Payment to terminate interest rate swap	$ 1,100,000
Not Designated as Hedging Instrument | Interest rate swap contracts
Derivative [Line Items]
Derivative Asset, Notional Amount		$ 327,569,000	53,593,000
Derivative Asset, Estimated Fair Value		8,764,000	1,332,000
Notional amount of terminated commitment		327,569,000	53,593,000
Derivative Liabilities, Estimated Fair Value		9,099,000	1,281,000
Not Designated as Hedging Instrument | Interest rate lock commitments
Derivative [Line Items]
Derivative Asset, Notional Amount		78,720,000	73,422,000
Derivative Asset, Estimated Fair Value		1,627,000	1,131,000
Not Designated as Hedging Instrument | Forward loan sales contracts
Derivative [Line Items]
Derivative Asset, Notional Amount		104,543,000	126,836,000
Derivative Asset, Estimated Fair Value		330,000	286,000
Designated as Hedging Instrument | Interest rate swap contracts
Derivative [Line Items]
Notional amount of terminated commitment		0	100,000,000
Derivative Liabilities, Estimated Fair Value		$ 0	$ 33,000