Share Repurchase Plan - Narrative (Details) - 2016 Stock Repurchase Program - USD ($)	9 Months Ended	14 Months Ended
	Sep. 30, 2017	Jun. 30, 2017	May 31, 2016
Class of Stock [Line Items]
Amount authorized by the company's Board of Directors (not more than)			$ 30,000,000
Common stock repurchased under share repurchase program (in shares)	0	305,183
Average cost per share (in dollars per share)	$ 24.43
Treasury stock, value, acquired	$ 7,500,000