Share Repurchase Plan - Repurchase Activity (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2016	Dec. 31, 2017	May 31, 2016
Equity [Abstract]
Total authorized repurchase amount			$ 30,000,000	$ 30,000,000
Total value of shares repurchased	$ 7,500,000	$ 7,500,000
Total remaining authorized repurchase amount	$ 22,500,000