Capital Stock and Share-Based Compensation - Equity Transactions (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019
Increase (Decrease) in Stockholders' Equity
Stockholder's equity beginning balance	$ 67,777	$ 67,469	$ 64,008	$ 62,354	$ 67,469	$ 62,354
Exercise of stock options (in shares)					662,965
Exercise of stock options	726	1,198	182	185
Share-based compensation	465	502	378	343
Deferred compensation issuance	78
Stock dividends to Carilion Clinic			0	0
Net income	1,369	(1,116)	841	1,126	$ 253	1,967
Forfeitures of restricted stock	(410)	(276)
Purchase of treasury stock	(204)		(220)
Stockholder's equity ending balance	$ 69,801	$ 67,777	$ 65,189	$ 64,008	$ 69,801	$ 65,189
Preferred Stock
Increase (Decrease) in Stockholders' Equity
Beginning balance (in shares)	0	0	1,321,514	1,321,514	0	1,321,514
Stockholder's equity beginning balance	$ 0	$ 0	$ 1	$ 1	$ 0	$ 1
Ending balance (in shares)	0	0	1,321,514	1,321,514	0	1,321,514
Stockholder's equity ending balance	$ 0	$ 0	$ 1	$ 1	$ 0	$ 1
Common Stock
Increase (Decrease) in Stockholders' Equity
Beginning balance (in shares)	30,486,577	30,149,105	28,145,713	27,956,401	30,149,105	27,956,401
Stockholder's equity beginning balance	$ 32	$ 32	$ 30	$ 30	$ 32	$ 30
Exercise of stock options (in shares)	346,461	316,504	207,786	189,312
Share-based compensation (in shares)	11,600	55,668
Deferred compensation issuance (in shares)	47,377
Forfeitures of restricted stock (in shares)	(61,530)	(34,700)
Purchase of treasury stock (in shares)	(32,950)		(52,733)
Ending balance (in shares)	30,797,535	30,486,577	28,300,766	28,145,713	30,797,535	28,300,766
Stockholder's equity ending balance	$ 32	$ 32	$ 30	$ 30	$ 32	$ 30
Treasury Stock
Increase (Decrease) in Stockholders' Equity
Beginning balance (in shares)	1,639,791	1,639,791	1,253,105	1,253,105	1,639,791	1,253,105
Stockholder's equity beginning balance	$ (4,337)	$ (4,337)	$ (2,117)	$ (2,117)	$ (4,337)	$ (2,117)
Purchase of treasury stock (in shares)	32,950		52,733
Purchase of treasury stock	$ (204)		$ (220)
Ending balance (in shares)	1,672,741	1,639,791	1,305,838	1,253,105	1,672,741	1,305,838
Stockholder's equity ending balance	$ (4,541)	$ (4,337)	$ (2,337)	$ (2,117)	$ (4,541)	$ (2,337)
Additional Paid-in Capital
Increase (Decrease) in Stockholders' Equity
Stockholder's equity beginning balance	89,446	88,022	86,356	85,745	88,022	85,745
Exercise of stock options	726	1,198	182	185
Share-based compensation	465	501	378	343
Deferred compensation issuance	78
Stock dividends to Carilion Clinic			90	83
Forfeitures of restricted stock	(410)	(275)
Stockholder's equity ending balance	90,305	89,446	87,006	86,356	90,305	87,006
Accumulated Deficit
Increase (Decrease) in Stockholders' Equity
Stockholder's equity beginning balance	(17,364)	(16,248)	(20,262)	(21,305)	(16,248)	(21,305)
Stock dividends to Carilion Clinic			(90)	(83)
Net income	1,369	(1,116)	841	1,126
Stockholder's equity ending balance	$ (15,995)	$ (17,364)	$ (19,511)	$ (20,262)	$ (15,995)	$ (19,511)