Accumulated Other Comprehensive Income (Loss) - Changes in Accumulated Other Comprehensive Income (Loss) by Component, Net of Tax (Detail) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Increase (Decrease) In Accumulated Other Comprehensive Income [Roll Forward]
Beginning Balance	$ (84,983)
Other comprehensive loss before reclassifications	5,055
Amounts reclassified from accumulated other comprehensive income	(5,875)
Net current-period other comprehensive loss	(820)	$ (27,793)	$ 94,985
Ending Balance	(85,803)	(84,983)
Gains/Losses on Cash Flow Hedges
Increase (Decrease) In Accumulated Other Comprehensive Income [Roll Forward]
Beginning Balance	87	423
Other comprehensive loss before reclassifications	(87)	(116)
Amounts reclassified from accumulated other comprehensive income	0	(220)
Net current-period other comprehensive loss	(87)	(336)
Ending Balance	0	87	423
Pension and Other Postretirement Benefits Items
Increase (Decrease) In Accumulated Other Comprehensive Income [Roll Forward]
Beginning Balance	(83,879)	(57,224)
Other comprehensive loss before reclassifications	6,475	(22,946)
Amounts reclassified from accumulated other comprehensive income	(5,875)	(3,709)
Net current-period other comprehensive loss	600	(26,655)
Ending Balance	(83,279)	(83,879)	(57,224)
Foreign Currency Items
Increase (Decrease) In Accumulated Other Comprehensive Income [Roll Forward]
Beginning Balance	(1,191)	(389)
Other comprehensive loss before reclassifications	(1,333)	(802)
Amounts reclassified from accumulated other comprehensive income	0	0
Net current-period other comprehensive loss	(1,333)	(802)
Ending Balance	(2,524)	(1,191)	(389)
Attributable to Parent
Increase (Decrease) In Accumulated Other Comprehensive Income [Roll Forward]
Beginning Balance	$ (84,983)	(57,190)
Other comprehensive loss before reclassifications		(23,864)
Amounts reclassified from accumulated other comprehensive income		(3,929)
Net current-period other comprehensive loss		(27,793)
Ending Balance		$ (84,983)	$ (57,190)

Increase (Decrease) In Accumulated Other Comprehensive Income [Roll Forward]

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Accumulated change in equity from transactions and other events and circumstances from non-owner sources, net of tax effect, at period end. Excludes Net Income (Loss), and accumulated changes in equity from transactions resulting from investments by owners and distributions to owners. Includes foreign currency translation items, certain pension adjustments, unrealized gains and losses on certain investments in debt and equity securities, other than temporary impairment (OTTI) losses related to factors other than credit losses on available-for-sale and held-to-maturity debt securities that an entity does not intend to sell and it is not more likely than not that the entity will be required to sell before recovery of the amortized cost basis, as well as changes in the fair value of derivatives related to the effective portion of a designated cash flow hedge.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=36458714&loc=d3e637-108580

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-Publisher FASB
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-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 31
-Article 5

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
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Amount after tax, before reclassification adjustments of other comprehensive income (loss).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Amount after tax and reclassification adjustments of other comprehensive income (loss).

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Amount after tax of reclassification adjustments of other comprehensive income (loss).

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