Summary of Significant Accounting Policies - Additional Information (Detail) $ / shares in Units, $ in Thousands		3 Months Ended																12 Months Ended
		Dec. 31, 2018 USD ($) plan $ / shares shares		Sep. 30, 2018 USD ($) $ / shares	[1]	Jun. 30, 2018 USD ($) $ / shares	[1]	Mar. 31, 2018 USD ($) $ / shares	[1]	Dec. 31, 2017 USD ($) $ / shares		Sep. 30, 2017 USD ($) $ / shares	[2]	Jun. 30, 2017 USD ($) $ / shares		Mar. 31, 2017 USD ($) $ / shares	[2]	Dec. 31, 2018 USD ($) plan $ / shares shares		Dec. 31, 2017 USD ($) $ / shares		Dec. 31, 2016 USD ($) $ / shares		Jan. 01, 2018 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Accounts Receivable, Net, Current		$ 511,332								$ 454,637								$ 511,332		$ 454,637
Inventory, Net		$ 634,806								721,290								$ 634,806		721,290
Stock split ratio (in shares)														2								2
Adoption of accounting standards update related to reclassification of certain tax effects																				(22,085)
Number of stock-based compensation plans | plan		1																1
Operating Income (Loss)																		$ 412,100		356,990		$ 299,730
Net income		$ 38,191	[1]	$ 84,739		$ 55,343		$ 45,721		$ 146,119	[2]	$ 72,382		$ 27,926	[2]	$ 23,232		$ 223,994		$ 269,659		$ 153,351
Earnings Per Share, Diluted | $ / shares		$ 0.34	[1],[3]	$ 0.76	[3]	$ 0.50	[3]	$ 0.41	[3]	$ 1.31	[2],[3]	$ 0.65	[3]	$ 0.25	[2],[3]	$ 0.21	[3]	$ 2.01	[4]	$ 2.42	[4]	$ 1.27	[4]
Other assets, net		$ 239,900								$ 275,113								$ 239,900		$ 275,113
Accrued liabilities		127,342								123,602								127,342		123,602
Other liabilities		(216,525)								(220,211)								(216,525)		(220,211)
Reclassification from other comprehensive loss to retained earnings resulting from Tax Cuts and Jobs Act																				22,100
Deferred Income Tax Liabilities, Net		268,036								262,394								268,036		262,394
Retained Earnings (Accumulated Deficit)		1,997,785								$ 1,809,845								1,997,785		1,809,845
Cost of Goods Sold	[5]																	3,759,112		3,455,306		$ 3,101,065
Selling, general and administrative expenses (a)	[5]																	308,376		305,173		219,926
Pension and Other Postretirement Benefits Cost (Reversal of Cost)	[5]																	(36,966)		(33,441)		(26,868)
Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Expected additional long-term assets and related lease liabilities		160,000																160,000
Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Expected additional long-term assets and related lease liabilities		$ 180,000																$ 180,000
Building
Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment, estimated useful life (in years)																		35 years
Machinery and Equipment [Member] | Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment, estimated useful life (in years)																		3 years
Machinery and Equipment [Member] | Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment, estimated useful life (in years)																		20 years
Customer Relationships [Member]
Summary Of Significant Accounting Policies [Line Items]
Finite-Lived Intangible Asset, Useful Life																		20 years
Other Intangible Assets [Member]
Summary Of Significant Accounting Policies [Line Items]
Finite-Lived Intangible Asset, Useful Life																		8 years
Restricted stock units
Summary Of Significant Accounting Policies [Line Items]
Number of common shares issuable per restricted stock unit (in shares) | shares		1																1
Accounting Standards Update 2014-09 [Member] | Difference between Revenue Guidance in Effect before and after Topic 606 [Member]
Summary Of Significant Accounting Policies [Line Items]
Accounts Receivable, Net, Current																								$ 69,400
Inventory, Net																								(56,600)
Accrued liabilities																								900
Deferred Income Tax Liabilities, Net																								2,800
Retained Earnings (Accumulated Deficit)																								$ 9,100
Accounting Standards Update 2017-07 [Member]
Summary Of Significant Accounting Policies [Line Items]
Cost of Goods Sold																				26,600		21,700
Selling, general and administrative expenses (a)																				6,800		5,200
Pension and Other Postretirement Benefits Cost (Reversal of Cost)																				$ (33,400)		$ (26,900)

[1] The first, second, third and fourth quarters of 2018 include rationalization charges of $0.7 million, $0.5 million, $0.3 million and $4.8 million, respectively. The second quarter of 2018 includes a loss on early extinguishment of debt of $2.5 million.

[2] The first, second, third and fourth quarters of 2017 include rationalization charges of $0.9 million, $3.0 million, $0.6 million and $1.3 million, respectively. The first, second, third and fourth quarters of 2017 includes costs attributed to announced acquisitions of $13.2 million, $9.8 million, $0.8 million and $0.9 million, respectively. The first and second quarters of 2017 include a loss on early extinguishment of debt of $2.7 million and $4.4 million, respectively. The fourth quarter of 2017 includes the benefit from effective tax rate adjustments totaling $110.9 million primarily related to the remeasurement of net deferred tax liabilities to reflect the lower future cash tax obligations as a result of the reduction in the federal corporate tax rate under the 2017 Tax Act.

[3] Net income per share data is computed independently for each of the periods presented. Accordingly, the sum of the quarterly earnings per share amounts may not equal the total for the year.

[4] Per share amounts for 2016 have been retroactively adjusted for the two-for-one stock split discussed in Note 1.

[5] Cost of goods sold, selling, general and administrative expenses and other pension and postretirement income include the impact of the Accounting Standards Update issued by the Financial Accounting Standards Board which amended the presentation of net periodic pension and postretirement benefit costs to report certain components, including interest cost, expected return on the plan assets, amortization of prior service cost or credits and actuarial gains and losses, separately. For 2017 and 2016, these items have been reclassified from cost of goods sold and selling, general and administrative expenses to other pension and postretirement income.