Recent Accounting Pronouncements - Summary of Adjustments to Accounts on Condensed Consolidated Statement of Cash Flows (Detail) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018		Sep. 30, 2017
Recent Accounting Pronouncements [Line Items]
Net loss		$ (12,620)	$ (12,527)	$ (73,561)		$ (65,650)
Deferred income taxes				(32,735)		(36,150)
Changes in operating assets and liabilities:
Accounts receivable, net				(95,884)		$ (21,598)
Net cash used in operating activities				(29,166)
Adjustments
Recent Accounting Pronouncements [Line Items]
Net loss	[1]	(1,168)		(21,756)	[2]
Deferred income taxes	[2]			(6,473)
Changes in operating assets and liabilities:
Accounts receivable, net	[2]			28,229
Net cash used in operating activities	[2]			0
Balance Without Adoption of ASC 606
Recent Accounting Pronouncements [Line Items]
Net loss		$ (13,788)		(95,317)
Deferred income taxes				(39,208)
Changes in operating assets and liabilities:
Accounts receivable, net				(67,655)
Net cash used in operating activities				$ (29,166)

[1] The adoption of ASC 606 resulted in additional revenues recognized in the first nine months of 2018, which in turn generated additional deferred tax liabilities that reduced the Company’s benefit from income taxes. The benefit from income taxes amount has been calculated using the Company’s estimated statutory rate.

[2] The adoption of ASC 606 resulted in decreased Net Loss and increased Accounts Receivable, Net due to additional revenues recognized in the first nine months of 2018, which in turn generated additional deferred tax liabilities that reduced net Deferred Tax Assets. The amount of deferred income taxes has been calculated using the Company’s estimated statutory rate.