Components of Accumulated Other Comprehensive Income (Loss) included in Stockholders' Equity (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2013
Statement Of Income And Comprehensive Income [Abstract]
Unrealized holding gain (loss) on investment, Beginning balance	$ (1,875)	$ (2,316)
Other comprehensive income (loss)	158	599
Amounts reclassified from AOCI
Net current period other comprehensive income (loss)	158	599
Unrealized holding gain (loss) on investment, Ending balance	(1,717)	(1,717)
Deferred gain (loss) on derivatives, Beginning balance	(58,316)	11,735
Other comprehensive income (loss)	24,767	(46,246)
Amounts reclassified from AOCI	320	1,282
Net current period other comprehensive income (loss)	25,087	(44,964)
Deferred gain (loss) on derivatives, Ending balance	(33,229)	(33,229)
Foreign currency gain (loss), Beginning balance	(2,886)	(3,366)
Other comprehensive income (loss)	(1,245)	(765)
Amounts reclassified from AOCI
Net current period other comprehensive income (loss)	(1,245)	(765)
Foreign currency gain (loss), Ending balance	(4,131)	(4,131)
Defined benefit pension plans gain (loss), Beginning balance	(93,596)	(100,466)
Other comprehensive income (loss)
Amounts reclassified from AOCI	3,438
Net current period other comprehensive income (loss)	3,438	10,308
Defined benefit pension plans gain (loss), Ending balance	(90,158)	(90,158)
Accumulated other comprehensive income, Beginning balance	(156,673)	(94,413)
Other comprehensive income (loss)	23,680	(46,412)
Amounts reclassified from AOCI	3,758	11,590
Net current period other comprehensive income (loss)	27,438	(34,822)
Accumulated other comprehensive income, Ending balance	$ (129,235)	$ (129,235)