Commitments, Contingencies and Other Matters (Narrative) (Detail) shares in Thousands, $ in Thousands	1 Months Ended		3 Months Ended		6 Months Ended
	Dec. 21, 2016 USD ($) shares	Jun. 30, 2009 USD ($)	Dec. 31, 2018 USD ($) Entity shares	Dec. 31, 2017 shares	Dec. 31, 2018 USD ($) Entity shares	Dec. 31, 2017 USD ($) shares	Jun. 30, 2018 USD ($)
Commitments and Contingencies Disclosure [Line Items]
Environmental charge						$ 902
Citron and Lucid
Commitments and Contingencies Disclosure [Line Items]
Deferred payment	$ 50,000
Interest rate	5.00%
Number of shares to be issued | shares	5,122		5,122	5,122	5,122	5,122
Purchase price, earn-out period	5 years
Purchase price, earn-out amount	$ 50,000
PRP Group
Commitments and Contingencies Disclosure [Line Items]
Loss contingency, damages sought					$ 1,700
Arsynco
Commitments and Contingencies Disclosure [Line Items]
Accrual for environmental loss contingencies			$ 4,010		$ 4,010		$ 5,746
Arsynco | Berry's Creek Study Area
Commitments and Contingencies Disclosure [Line Items]
Number of potentially responsible parties | Entity			150		150
Arsynco | Agreement to sell the Arsynco property | Environmental Remediation property for sale
Commitments and Contingencies Disclosure [Line Items]
Expected sale of property value							6,340
Arsynco | Minimum
Commitments and Contingencies Disclosure [Line Items]
Estimated cost of environmental remediation obligations					$ 22,900
Arsynco | Maximum
Commitments and Contingencies Disclosure [Line Items]
Estimated cost of environmental remediation obligations					24,700
BASF
Commitments and Contingencies Disclosure [Line Items]
Partial reimbursement of environmental remediation costs previously expensed		$ 550
Gain related to partial reimbursement		550
Environmental remediation costs expensed in prior years		$ 1,200
Future remediation costs receivable			$ 1,805		1,805		$ 2,586
Subsidiary
Commitments and Contingencies Disclosure [Line Items]
Amount expected to be paid for product registrations and various task force groups			$ 5,644		$ 5,644