Schedule of Trade Receivables, Contract Assets and Contract Liabilities from Contracts with Customers (Detail) $ in Thousands	Jun. 30, 2018 USD ($)
Trade Receivables
Contract with Customer Asset and Liability [Line Items]
Contract with customer asset, balance	$ 9,246
Accrued Revenues
Contract with Customer Asset and Liability [Line Items]
Contract with customer asset, balance	1,718
Accrued Revenues \| Royalties
Contract with Customer Asset and Liability [Line Items]
Contract with customer asset, balance	7,035
Deferred Revenue
Contract with Customer Asset and Liability [Line Items]
Contract with customer liability, balance	$ 2,717

Amount of obligation to transfer good or service to customer for which consideration has been received or is receivable, classified as current.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=82913815&loc=SL49130532-203044

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=82913815&loc=SL49130531-203044

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 8
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109196051&loc=SL49130549-203045

Name:	us-gaap_ContractWithCustomerLiabilityCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant