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		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Accounting Changes And Error Corrections [Line Items]
Net income (loss)	$ (13,784)	$ 125,961	$ (44,277)	$ 112,234
Adjustments to reconcile net income to net cash provided by (used by) operating activities:
Depreciation and amortization	$ 21,259	13,384	51,798	39,006
Share of net income from joint venture, net of cash dividends received			(1,744)	17
Deferred income taxes			(14,737)	70
Other			255	(123)
Changes in operating assets and liabilities, net of acquisitions:
Accounts receivable			(19,656)	(14,867)
Inventories			(18,207)	(10,328)
Accounts payable			(1,681)	(19,409)
Other			5,485	(2,765)
Other			650	1,184
Cash flows from financing activities
Cash paid for debt issuance or prepayment costs			(20,703)	(38,130)
Other			$ (3,161)	(490)
As Previously Reported
Accounting Changes And Error Corrections [Line Items]
Net income (loss)		132,895		118,561
Adjustments to reconcile net income to net cash provided by (used by) operating activities:
Depreciation and amortization		13,075		38,432
Loss on extinguishment of debt and write-off of debt issuance costs				8,054
Gain on disposal of discontinued operations, net of tax and cost to sell				129,353
Deferred income taxes				0
Other				439
Changes in operating assets and liabilities, net of acquisitions:
Accounts receivable				(15,094)
Inventories				(10,764)
Accounts payable				(19,178)
Other				(1,674)
Net cash provided by (used by) operating activities				285
Proceeds from disposals of property, plant and equipment				639
Other				0
Net cash provided by (used by) investing activities				332,401
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				2,945
Shares withheld to satisfy income tax withholding				(580)
Principal payments on capital leases				2,855
Other				0
Net cash provided by (used by) financing activities				(1,080)
Adjustment
Accounting Changes And Error Corrections [Line Items]
Net income (loss)		(6,934)		(6,327)
Adjustments to reconcile net income to net cash provided by (used by) operating activities:
Depreciation and amortization		309		574
Gain on disposal of discontinued operations, net of tax and cost to sell				(6,343)
Other				(545)
Changes in operating assets and liabilities, net of acquisitions:
Accounts receivable				227
Inventories				436
Accounts payable				(231)
Other				(1,021)
Net cash provided by (used by) operating activities				(544)
Other				545
Net cash provided by (used by) investing activities				545
Reclasses
Adjustments to reconcile net income to net cash provided by (used by) operating activities:
Loss on extinguishment of debt and write-off of debt issuance costs				31,585
Share of net income from joint venture, net of cash dividends received				17
Deferred income taxes				70
Other				(17)
Changes in operating assets and liabilities, net of acquisitions:
Other				(70)
Net cash provided by (used by) operating activities				31,585
Proceeds from disposals of property, plant and equipment				(639)
Other				639
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				(2,945)
Shares withheld to satisfy income tax withholding				580
Principal payments on capital leases				(2,855)
Other				(490)
Net cash provided by (used by) financing activities				(31,585)
Continuing Operations As Revised
Accounting Changes And Error Corrections [Line Items]
Net income (loss)		125,961		112,234
Adjustments to reconcile net income to net cash provided by (used by) operating activities:
Depreciation and amortization		$ 13,384		39,006
Loss on extinguishment of debt and write-off of debt issuance costs				39,639
Gain on disposal of discontinued operations, net of tax and cost to sell				123,010
Deferred income taxes				70
Other				(123)
Changes in operating assets and liabilities, net of acquisitions:
Accounts receivable				(14,867)
Inventories				(10,328)
Accounts payable				(19,409)
Other				(2,765)
Net cash provided by (used by) operating activities				31,326
Proceeds from disposals of property, plant and equipment				0
Other				1,184
Net cash provided by (used by) investing activities				332,946
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				(490)
Net cash provided by (used by) financing activities				$ (32,665)