CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Statement [Abstract]
Total revenue, net	$ 1,188,236	$ 992,075	$ 882,734
Costs and Expenses:
Cost of goods sold	435,511	349,089	326,542
Research and development	63,455	58,155	50,895
Selling, general and administrative	624,096	455,629	415,757
Intangible asset amortization	20,370	13,862	9,953
Total costs and expenses	1,143,432	876,735	803,147
Operating income	44,804	115,340	79,587
Interest income	255	24	30
Interest expense	(35,019)	(25,803)	(23,534)
Other income, net	1,345	845	4,588
Income from continuing operations before income taxes	11,385	90,406	60,671
(Benefit from) provision for income taxes	(53,358)	15,842	53,820
Net income from continuing operations	64,743	74,564	6,851
Loss from discontinued operations (net of tax benefit)	0	0	(10,370)
Net income (loss)	$ 64,743	$ 74,564	$ (3,519)
Net income (loss) per share - basic:
Income from continuing operations (in dollars per share)	$ 0.84	$ 1.00	$ 0.10
Loss from discontinued operations (in dollars per share)	0.00	0.00	(0.15)
Net income (loss) per share - basic (in dollars per share)	0.84	1.00	(0.05)
Net income (loss) per share - diluted:
Income from continuing operations (in dollars per share)	0.82	0.94	0.10
Loss from discontinued operations (in dollars per share)	0.00	0.00	(0.15)
Net income (loss) per share - diluted (in dollars per share)	$ 0.82	$ 0.94	$ (0.05)
Weighted average common shares outstanding (See Note 12):
Basic (in shares)	76,897	74,386	68,990
Diluted (in shares)	79,121	79,194	71,354