Share Repurchase Plan - Narrative (Details) - 2016 Stock Repurchase Program - USD ($)	8 Months Ended	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	May 31, 2016
Equity, Class of Treasury Stock [Line Items]
Amount authorized by the company's Board of Directors (not more than)		$ 30,000,000		$ 30,000,000
Common stock purchased under share repurchase program (in shares)	305,183	0	305,183