Subsequent Events Subsequent Events (Details) - USD ($) shares in Thousands, $ in Thousands	1 Months Ended	3 Months Ended
	May 09, 2018	Mar. 31, 2018	Mar. 31, 2017
Subsequent Event [Line Items]
Treasury Stock, Shares, Acquired		100	0
Payments for Repurchase of Common Stock		$ 1,293	$ 0
Subsequent Event [Member]
Subsequent Event [Line Items]
Treasury Stock, Shares, Acquired	900
Payments for Repurchase of Common Stock	$ 16,600