Leases - Summary of Information Related to ROU Assets and Related Lease Liabilities (Parenthetical) (Detail) - USD ($) $ in Thousands		3 Months Ended	6 Months Ended
Jan. 01, 2019	Jun. 30, 2019	Jun. 30, 2019
Lessee Lease Description [Line Items]
Operating lease	$ 25,800	$ 1,819	$ 28,514
ASU 2016-02 [Member]
Lessee Lease Description [Line Items]
Operating lease			$ 2,700

Amount of increase in right-of-use asset obtained in exchange for operating lease liability.

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 55
-Paragraph 53
-URI http://asc.fasb.org/extlink&oid=77888399&loc=SL77918982-209971

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (g)(2)
-URI http://asc.fasb.org/extlink&oid=77888426&loc=SL77918686-209980

Name:	us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration