Accumulated Other Comprehensive Income (Loss) - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Accumulated Other Comprehensive Income (Loss) [Line Items]
Benefit plans expenses reclassified from accumulated OCI to income	$ 1.2	$ 1.9
Deferred gains and losses on derivatives reclassified from accumulated OCI to income	$ 2.0	$ 6.1