Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Cash Paid During the Period For:
Income taxes	$ 184	$ 89
Interest, net	627	1,343
Operating lease liabilities	1,836
Non-Cash Financing and Investing Transactions:
ROU assets obtained from new operating leases	817
Unsettled repurchases of common stock	369	0
Employee stock purchase plan	140	132
Shares tendered in payment of exercise price of stock options	$ 0	46
Proceeds from income tax refunds		$ 6,800