Consolidated Statements of Cash Flows - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017		Dec. 31, 2016
Cash flows from operating activities:
Net income		$ 62.7	$ 82.6		$ 51.8
Adjustments to reconcile to net cash provided by (used in) operating activities:
Stock-based compensation expense		23.2	15.2		18.5
Depreciation and amortization		62.2	42.6		38.2
Income taxes		8.6	3.3		5.2
Change in fair value of contingent obligations		3.1	7.8		(10.8)
Impairment and abandonment of long-lived assets		0.0	1.9		5.6
Excess tax benefits from stock-based compensation		0.0	0.0		(10.6)
Other		1.1	1.0		1.0
Changes in operating assets and liabilities:
Accounts receivable		(94.2)	(4.8)		(22.4)
Inventories		(1.9)	6.1		(9.0)
Income taxes		(5.1)	20.1		(3.4)
Prepaid expenses and other assets		(7.9)	(3.7)		(2.1)
Accounts payable		(7.0)	16.1		(14.8)
Accrued expenses and other liabilities		(11.6)	1.6		0.6
Accrued compensation		8.4	3.3		2.2
Deferred revenue		0.2	15.0		4.6
Net cash provided by operating activities		41.8	208.1		54.6
Cash flows from investing activities:
Purchases of property, plant and equipment and other		(72.1)	(54.8)		(76.2)
Proceeds from sale of assets		2.6	0.0		0.0
Asset acquisitions		0.0	(77.6)		0.0
Business acquisitions, net of cash acquired		(827.7)	(117.5)		0.0
Net cash used in investing activities		(897.2)	(249.9)		(76.2)
Cash flows from financing activities:
Proceeds from long-term debt obligations		798.0	0.0		0.0
Issuance of common stock upon exercise of stock options		15.9	19.3		17.1
Excess tax benefits from stock-based compensation		0.0	0.0		10.6
Debt issuance costs		(13.4)	(1.4)		0.0
Taxes paid on behalf of employees for equity activity		(6.6)	(4.3)		(1.1)
Principal payments on long-term indebtedness		(2.8)	0.0		0.0
Payments of notes payable to Aptevo		0.0	(20.0)		0.0
Distribution to Aptevo		0.0	0.0		(45.0)
Contingent consideration payments		(3.4)	(10.9)		(1.4)
Restricted cash		1.1	(1.0)		0.0
Purchase of treasury stock		(0.1)	(33.1)		0.0
Net cash provided by (used in) financing activities		788.7	(51.4)		(19.8)
Effect of exchange rate changes on cash, cash equivalents and restricted cash		(0.2)	0.0		0.1
Net increase in cash, cash equivalents and restricted cash		(66.9)	(93.2)		(41.3)
Cash, cash equivalents and restricted cash at beginning of year	[1]	179.3	272.5
Cash, cash equivalents and restricted cash at end of year	[1]	112.4	179.3		272.5
Cash and cash equivalents at beginning of year		178.3	271.5	[1]	312.8	[1]
Cash and cash equivalents at end of year		112.2	178.3		271.5	[1]
Supplemental disclosure of cash flow information:
Cash paid during the year for interest		10.2	8.4		8.2
Cash paid during the year for income taxes		14.0	12.0		10.1
Supplemental information on non-cash investing and financing activities:
Issuance of common stock to acquire Adapt Pharma		37.7	0.0		0.0
Purchases of property, plant and equipment unpaid at year end		$ 14.7	$ 4.6		$ 13.5

[1] As of December 31, 2018 and December 31, 2017, the balance includes restricted cash of $0.2 million and $1.0 million, respectively.