Nature of Operations and Summary of Significant Policies - Narrative (Details)		3 Months Ended		12 Months Ended
	Jan. 26, 2017 $ / shares	Dec. 31, 2016 USD ($) portfolio_class $ / shares	Dec. 31, 2015 USD ($) $ / shares	Sep. 30, 2016 USD ($)	Dec. 31, 2010 agreement	Sep. 30, 2015 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Maturity period of loans and loan commitments		5 years
Number of portfolio classes | portfolio_class		6
FDIC Indemnification, number of loss share agreements entered | agreement					2
FDIC Indemnification, expected reimbursement rate (as a percent)				80.00%
FDIC Clawback Liability, payment period following termination or maturity of agreement				45 days
Impairment related to goodwill		$ 0	$ 0
Impairment of intangible assets		0	0
Loan servicing rights, valuation allowance		$ (8,000)	$ 0	$ (13,000)		$ 0
Common stock dividends declared (in dollars per share) | $ / shares		$ 0.17	$ 0.14
Subsequent event
Accounts, Notes, Loans and Financing Receivable [Line Items]
Common stock dividends declared (in dollars per share) | $ / shares	$ 0.17
Residential loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
FDIC Indemnification, number of loss share agreements entered | agreement					1
Minimum
Accounts, Notes, Loans and Financing Receivable [Line Items]
Maturity period of loans and loan commitments		5 years
Maximum
Accounts, Notes, Loans and Financing Receivable [Line Items]
Maturity period of loans and loan commitments		15 years