Summary of Significant of Accounting Policies - Changes in Accumulated Other Comprehensive (Loss) Income by Component (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Components Of Accumulated Other Comprehensive Income Loss [Line Items]
Beginning balance	$ (501,492)
Other comprehensive income (loss) before reclassifications, net of tax	56,917
Amounts reclassified from accumulated other comprehensive (loss) income, net of tax	46,920
Net current period other comprehensive income (loss)	103,837	(19,454)	(183,686)
Ending balance	(397,655)	(501,492)
Pension Benefits [Member]
Components Of Accumulated Other Comprehensive Income Loss [Line Items]
Beginning balance	(629,907)
Other comprehensive income (loss) before reclassifications, net of tax	223,991
Amounts reclassified from accumulated other comprehensive (loss) income, net of tax	46,837
Net current period other comprehensive income (loss)	270,828
Ending balance	(359,079)
Other Post-Retirement Benefits [Member]
Components Of Accumulated Other Comprehensive Income Loss [Line Items]
Beginning balance	(2,669)
Other comprehensive income (loss) before reclassifications, net of tax	1,629
Amounts reclassified from accumulated other comprehensive (loss) income, net of tax	83
Net current period other comprehensive income (loss)	1,712
Ending balance	(957)
Foreign Currency Translation [Member]
Components Of Accumulated Other Comprehensive Income Loss [Line Items]
Beginning balance	131,084
Other comprehensive income (loss) before reclassifications, net of tax	(168,703)
Amounts reclassified from accumulated other comprehensive (loss) income, net of tax
Net current period other comprehensive income (loss)	(168,703)
Ending balance	$ (37,619)