CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Statement [Abstract]
Total revenue, net	$ 992,075	$ 882,734	$ 796,717
Costs and Expenses:
Cost of goods sold	349,089	326,542	302,946
Research and development	58,155	50,895	43,559
Selling, general and administrative	455,629	415,757	375,545
Intangible asset amortization	13,862	9,953	6,810
Total costs and expenses	876,735	803,147	728,860
Operating income	115,340	79,587	67,857
Interest income	24	30	168
Interest expense	(25,803)	(23,534)	(21,967)
Other income (expense), net	845	4,588	(492)
Income from continuing operations before income taxes	90,406	60,671	45,566
Provision for income taxes	15,842	53,820	9,271
Net income from continuing operations	74,564	6,851	36,295
Loss from discontinued operations (net of tax benefit)	0	(10,370)	(2,291)
Net income (loss)	$ 74,564	$ (3,519)	$ 34,004
Net income (loss) per share - basic:
Income from continuing operations (in dollars per share)	$ 1.00	$ 0.10	$ 0.56
Loss from discontinued operations (in dollars per share)	0.00	(0.15)	(0.04)
Net income (loss) per share - basic (in dollars per share)	1.00	(0.05)	0.52
Net income (loss) per share - diluted:
Income from continuing operations (in dollars per share)	0.94	0.10	0.55
Loss from discontinued operations (in dollars per share)	0.00	(0.15)	(0.03)
Net income (loss) per share - diluted (in dollars per share)	$ 0.94	$ (0.05)	$ 0.52
Weighted average common shares outstanding (See Note 12):
Basic (in shares)	74,386	68,990	64,864
Diluted (in shares)	79,194	71,354	65,920