Goodwill - Narrative (Details) - USD ($)		3 Months Ended	12 Months Ended
	Jun. 12, 2015	Mar. 31, 2016	Dec. 31, 2016	Dec. 31, 2015	Apr. 17, 2015	Dec. 31, 2014
Business Acquisition [Line Items]
Goodwill			$ 244,000,000	$ 243,129,000		$ 202,724,000
Measurement period adjustment			871,000
Goodwill reduction				8,474,000
Goodwill impairment loss			$ 0	0
FMIG
Business Acquisition [Line Items]
Goodwill reduction	$ 8,474,000
Merger with Ameriana Bancorp
Business Acquisition [Line Items]
Goodwill				$ 38,624,000
Measurement period adjustment		$ 871,000
Merger with C Financial Corporation
Business Acquisition [Line Items]
Goodwill					$ 11,126,000