Related Party Transactions - Summary of Various Components of Parent Company Debt Facilities Represents Related Party Balances Outstanding (Detail) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Related Party Transaction [Line Items]
Total	$ 37,015	$ 32,826
Privateer Holdings Start Up Loans [Member]
Related Party Transaction [Line Items]
Total	2,069	1,731
Privateer Holding [Member]
Related Party Transaction [Line Items]
Total	37,015	32,826
Privateer Holding [Member] \| Privateer Holdings Credit Facility [Member]
Related Party Transaction [Line Items]
Total	26,837	24,700
Privateer Holding [Member] \| Privateer Holdings Construction Facility [Member]
Related Party Transaction [Line Items]
Total	8,108	6,395
Privateer Holding [Member] \| Privateer Holdings Start Up Loans [Member]
Related Party Transaction [Line Items]
Total	$ 2,070	$ 1,731

Carrying amount as of the balance sheet date of obligations due all related parties. For classified balance sheets, represents the current portion of such liabilities (due within one year or within the normal operating cycle if longer).

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(k)(1))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.19(a))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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