Share Repurchase Plan - Repurchase Activity (Details) - 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]
Total value of shares repurchased			$ 7,500,000
2016 Stock Repurchase Program
Equity, Class of Treasury Stock [Line Items]
Total number of shares repurchased (in shares)	305,183	0	305,183
Average price paid per share (in dollars per share)			$ 24.43
Total value of shares repurchased		$ 7,500,000	$ 7,500,000
Total authorized repurchase amount		30,000,000		$ 30,000,000
Total remaining authorized repurchase amount		$ 22,500,000