Components of Accumulated Other Comprehensive Income (Loss) included in Stockholders' Equity (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Statement Of Income And Comprehensive Income [Abstract]
Unrealized holding gain (loss) on investment, Beginning balance	$ (1,915)	$ (3,706)	$ (2,316)	$ (4,402)
Other comprehensive income (loss)	40	431	441	1,127
Amounts reclassified from AOCI
Net current period other comprehensive income (loss)	40	431	441	1,127
Unrealized holding gain (loss) on investment, Ending balance	(1,875)	(3,275)	(1,875)	(3,275)
Deferred gain (loss) on derivatives, Beginning balance	(5,819)	(1,657)	11,735	3,088
Other comprehensive income (loss) before reclassification	(55,563)	(18,164)	(71,013)	(24,051)
Amounts reclassified from AOCI	3,066	1,107	962	2,249
Net current period other comprehensive income (loss)	(52,497)	(17,057)	(70,051)	(21,802)
Deferred gain (loss) on derivatives, Ending balance	(58,316)	(18,714)	(58,316)	(18,714)
Foreign currency gain (loss), Beginning balance	3,848	(9,325)	(3,366)	(12,438)
Other comprehensive income (loss) before reclassification	(6,734)	3,326	480	6,439
Amounts reclassified from AOCI
Net current period other comprehensive income (loss)	(6,734)	3,326	480	6,439
Foreign currency gain (loss), Ending balance	(2,886)	(5,999)	(2,886)	(5,999)
Defined benefit pension plans gain (loss), Beginning balance	(96,811)	(85,233)	(100,466)	(88,278)
Other comprehensive income (loss) before reclassification
Amounts reclassified from AOCI	3,215	2,681	6,870	5,726
Net current period other comprehensive income (loss)	3,215	2,681	6,870	5,726
Defined benefit pension plans gain (loss), Ending balance	(93,596)	(82,552)	(93,596)	(82,552)
Accumulated other comprehensive income, Beginning balance	(100,697)	(99,921)	(94,413)	(102,030)
Other comprehensive income (loss) before reclassification	(62,257)	(14,407)	(70,092)	(16,485)
Amounts reclassified from AOCI	6,281	3,788	7,832	7,975
Net current period other comprehensive income (loss)	(55,976)	(10,619)	(62,260)	(8,510)
Accumulated other comprehensive income, Ending balance	$ (156,673)	$ (110,540)	$ (156,673)	$ (110,540)