Aggregate status of the plans and the amounts recognized in the consolidated financial statements (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Pension Plans, Defined Benefit [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Defined Benefit Plan Interest Cost	$ 7,403	$ 7,461
Other Pension Plans Defined Benefit Member
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Defined Benefit Plan Interest Cost	$ 407	$ 415