Prior Periods Financial Statement Revision - Schedule of Correction of Misstatements and Revision on Condensed Consolidated Statements of Cash Flow (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Accounting Changes And Error Corrections [Line Items]
Net loss	$ (24,511)	$ (21,138)	$ (30,494)	$ (13,727)
Adjustments to reconcile net loss to net cash provided by (used by) operating activities:
Other			180	102
Changes in operating assets and liabilities, net of acquisitions:
Income taxes receivable			(8,695)	(10,612)
Other			5,589	(8,136)
Other			625	624
Cash flows from financing activities
Cash paid for debt issuance or prepayment costs			(16,703)	(38,130)
Other			$ (2,410)	120
As Previously Reported [Member]
Accounting Changes And Error Corrections [Line Items]
Net loss		(21,529)		(14,122)
Adjustments to reconcile net loss to net cash provided by (used by) operating activities:
Depreciation and amortization				31,468
Gain on disposals or property, plant and equipment				(268)
Loss on extinguishment of debt and write-off of debt issuance costs				8,054
Other				638
Changes in operating assets and liabilities, net of acquisitions:
Income taxes receivable				(10,841)
Other				(7,247)
Net cash provided by (used by) operating activities				(15,552)
Proceeds from disposals of property, plant and equipment				356
Other				0
Net cash provided by (used by) investing activities				(20,302)
Cash flows from financing activities
Cash paid for debt issuance or prepayment costs				(6,545)
Proceeds from issuance of stock and exercise of stock options				2,592
Shares withheld to satisfy income tax withholding				(413)
Principal payments on capital leases				(2,059)
Other				0
Net cash provided by (used by) financing activities				39,762
Adjustment [Member]
Accounting Changes And Error Corrections [Line Items]
Net loss		391		395
Adjustments to reconcile net loss to net cash provided by (used by) operating activities:
Depreciation and amortization				265
Other				(268)
Changes in operating assets and liabilities, net of acquisitions:
Income taxes receivable				229
Other				(889)
Net cash provided by (used by) operating activities				(268)
Proceeds from disposals of property, plant and equipment				0
Other				268
Net cash provided by (used by) investing activities				268
Reclasses [Member]
Adjustments to reconcile net loss to net cash provided by (used by) operating activities:
Gain on disposals or property, plant and equipment				268
Loss on extinguishment of debt and write-off of debt issuance costs				31,585
Other				(268)
Changes in operating assets and liabilities, net of acquisitions:
Net cash provided by (used by) operating activities				31,585
Proceeds from disposals of property, plant and equipment				(356)
Other				356
Net cash provided by (used by) investing activities				0
Cash flows from financing activities
Cash paid for debt issuance or prepayment costs				(31,585)
Proceeds from issuance of stock and exercise of stock options				(2,592)
Shares withheld to satisfy income tax withholding				413
Principal payments on capital leases				2,059
Other				120
Net cash provided by (used by) financing activities				(31,585)
Continuing Operations As Revised [Member]
Accounting Changes And Error Corrections [Line Items]
Net loss		$ (21,138)		(13,727)
Adjustments to reconcile net loss to net cash provided by (used by) operating activities:
Depreciation and amortization				31,733
Gain on disposals or property, plant and equipment				0
Loss on extinguishment of debt and write-off of debt issuance costs				39,639
Other				102
Changes in operating assets and liabilities, net of acquisitions:
Income taxes receivable				(10,612)
Other				(8,136)
Net cash provided by (used by) operating activities				15,765
Proceeds from disposals of property, plant and equipment				0
Other				624
Net cash provided by (used by) investing activities				(20,034)
Cash flows from financing activities
Cash paid for debt issuance or prepayment costs				(38,130)
Proceeds from issuance of stock and exercise of stock options				0
Shares withheld to satisfy income tax withholding				0
Principal payments on capital leases				0
Other				120
Net cash provided by (used by) financing activities				$ 8,177