Fair Value Measurements (Narrative) (Detail) - USD ($) shares in Thousands, $ in Thousands	1 Months Ended		3 Months Ended		6 Months Ended		12 Months Ended
	Mar. 21, 2017	Dec. 21, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Jun. 30, 2018	Nov. 30, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unrealized gain on interest rate swap					$ 1,135
Principal amount								$ 143,750
Theoretical borrowing rate used to calculate fair value of debt								6.50%
Fair value of the notes			$ 109,000		109,000
Fair value of future issuance of shares			90,400		90,400
Human Health Segment - Rising Reporting Unit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Recognized non-cash goodwill impairment charge, before tax							$ 235,110
Foreign currency contract
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative, notional amount			61,904		61,904
Unrealized gains (losses) on hedging activities			362	$ (34)	693	$ 261
Interest rate swap | January 2019 Amendment
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash receipt from termination					1,145
Cash flow hedging | December 21, 2021 | Interest rate swap
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Additional interest cost rate of derivative	2.005%
Derivative, notional amount	$ 100,000
Derivative, expiration date	Dec. 21, 2021
Notional balance of derivative			$ 80,000		$ 80,000
Citron and Lucid
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Accrued contingent consideration							683
Number of shares to be issued		5,122	5,122	5,122	5,122	5,122
Reversed contingent consideration second quarter of fiscal 2019							$ 724