Selected Quarterly Financial Data (Unaudited) (Narrative) (Details) - USD ($) $ / shares in Units, $ in Thousands, shares in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Revenues	$ 264,865	$ 233,590	$ 238,263	$ 218,378	$ 242,444	$ 202,307	$ 212,820	$ 202,064	$ 955,097	$ 859,634	$ 796,392
Gross Profit	141,975	130,111	131,190	121,438	132,655	110,627	116,271	109,557	524,715	469,110	431,041
Net income	14,933	6,970	5,695	1,021	15,653	5,825	$ 8,719	$ 10,657	28,620	40,854	55,487
Business Combination, Acquisition Related Costs	1,900	1,700	$ 3,000	7,900	$ 1,300	1,100				1,100
Manufacturing consolidation costs	$ 1,400	$ 1,400
Incremental Common Shares Attributable to Dilutive Effect of Conversion of Debt Securities	0.6	0.2
Other expense				$ 3,900					5,188	0	0
Impairment charges						$ 4,200			$ 312	$ 4,212	$ 0
EPS:
Basic (in dollars per share)	$ 0.53	$ 0.25	$ 0.20	$ 0.04	$ 0.56	$ 0.21	$ 0.31	$ 0.38	$ 1.01	$ 1.45	$ 1.99
Diluted (in dollars per share)	$ 0.49	$ 0.23	$ 0.19	$ 0.04	$ 0.54	$ 0.20	$ 0.30	$ 0.37	$ 0.97	$ 1.41	$ 1.97