Supplemental Disclosure of Cash Flow and Non-Cash Investing and Financing Activities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Supplemental Cash Flow Elements [Abstract]
Cash paid for interest	$ 197	$ 127	$ 162
Income taxes paid	859	12,755	642
Purchases of equipment financed through accounts payable	1,168	1,343	831
Deferred financing costs	0	30	10
Additional paid-in capital related tax adjustments	0	0	(423)
Stock issuance of 441,009 shares in connection with acquisition of Stability	0	0	$ 3,347
Shares issued in conjunction with acquisition (in shares)			441,009
Stock issuance of 17,539 and 43,344 shares in exchange for services performed in 2017 and 2016, respectively	$ 0	$ 166	$ 346
Shares issued for services performed (in shares)		17,539	43,344