Accumulated Other Comprehensive Loss - Components of Accumulated Other Comprehensive Loss (Detail) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2013
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), net of tax, beginning balance	$ (475,826)	[1]
Other comprehensive income/(loss) before reclassifications	(38,607)
Amounts reclassified from accumulated other comprehensive loss	(89)
Net current-period other comprehensive income/ (loss)	(25,084)
Accumulated other comprehensive income (loss), net of tax, ending balance	(500,910)
Net Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified from accumulated other comprehensive loss	13,434
Fixed Assets [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified from accumulated other comprehensive loss	89
Gains and Losses on Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), net of tax, beginning balance	(6,727)
Other comprehensive income/(loss) before reclassifications	2,092
Net current-period other comprehensive income/ (loss)	2,890
Accumulated other comprehensive income (loss), net of tax, ending balance	(3,837)
Gains and Losses on Cash Flow Hedges [Member] | Net Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified from accumulated other comprehensive loss	709
Gains and Losses on Cash Flow Hedges [Member] | Fixed Assets [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified from accumulated other comprehensive loss	89
Defined Benefit Pension Items [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), net of tax, beginning balance	(472,333)
Net current-period other comprehensive income/ (loss)	12,725
Accumulated other comprehensive income (loss), net of tax, ending balance	(459,608)
Defined Benefit Pension Items [Member] | Net Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified from accumulated other comprehensive loss	12,725
Foreign Currency Items [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), net of tax, beginning balance	3,234
Other comprehensive income/(loss) before reclassifications	(40,699)
Net current-period other comprehensive income/ (loss)	(40,699)
Accumulated other comprehensive income (loss), net of tax, ending balance	$ (37,465)

[1] The year-end condensed consolidated balance sheet data was derived from audited financial statements, but does not include all disclosures required by accounting principles generally accepted in the United States of America.