Accumulated Other Comprehensive Income - Schedule of Amounts Reclassified from Accumulated Other Comprehensive Income (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Defined Benefit Plan Disclosure [Line Items]
Costs of products sold	$ (361,205)	$ (385,439)	$ (1,107,319)	$ (1,196,076)
Selling, general and administrative	(39,792)	(37,886)	(100,201)	(103,751)
Income tax provision	2,288	9,037	4,122	13,434
Net income	13,504	30,372	30,277	49,689
Reclassifications Out of Accumulated Other Comprehensive Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Net income	1,641	2,494	5,902	8,075
Reclassifications Out of Accumulated Other Comprehensive Income [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Costs and Expenses	4,986	3,804	14,960	11,413
Income tax provision	(1,896)	(1,441)	(5,686)	(4,325)
Net income	3,090	2,363	9,274	7,088
Reclassifications Out of Accumulated Other Comprehensive Income [Member] | Pension Benefits [Member] | Prior Service Costs [Member]
Defined Benefit Plan Disclosure [Line Items]
Costs of products sold	571	621	1,713	1,864
Selling, general and administrative	189	206	568	618
Reclassifications Out of Accumulated Other Comprehensive Income [Member] | Pension Benefits [Member] | Actuarial Losses [Member]
Defined Benefit Plan Disclosure [Line Items]
Costs of products sold	3,144	2,215	9,432	6,644
Selling, general and administrative	1,082	762	3,247	2,287
Reclassifications Out of Accumulated Other Comprehensive Income [Member] | Amortization of Deferred Benefit Other Plan Items [Member]
Defined Benefit Plan Disclosure [Line Items]
Costs and Expenses	(12)	57	(37)	171
Income tax provision	5	(22)	16	(66)
Net income	(7)	35	(21)	105
Reclassifications Out of Accumulated Other Comprehensive Income [Member] | Amortization of Deferred Benefit Other Plan Items [Member] | Prior Service Costs [Member]
Defined Benefit Plan Disclosure [Line Items]
Costs of products sold	(58)	(59)	(173)	(178)
Selling, general and administrative	(12)	(13)	(37)	(38)
Reclassifications Out of Accumulated Other Comprehensive Income [Member] | Amortization of Deferred Benefit Other Plan Items [Member] | Actuarial Losses [Member]
Defined Benefit Plan Disclosure [Line Items]
Costs of products sold	48	106	142	319
Selling, general and administrative	10	23	31	68
Reclassifications Out of Accumulated Other Comprehensive Income [Member] | Cash Flow Hedges [Member] | (Gains) Losses on Cash Flow Hedges [Member]
Defined Benefit Plan Disclosure [Line Items]
Costs of products sold	(1,972)	137	(4,595)	1,227
Income tax provision	530	(41)	1,244	(345)
Net income	$ (1,442)	$ 96	$ (3,351)	$ 882