Changes in accumulated other comprehensive income (loss) (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013
Balance, Foreign Currency Translation Adjustment	$ 3,178
Other comprehensive income, Foreign Currency Translation Adjustment	(2,034)
Amounts reclassified from accumulated other comprehensive income, Foreign Currency Translation Adjustment	0	[1]
Balance, Foreign Currency Translation Adjustment	1,144
Balance, Defined Benefit Pension Adjustment	(21,544)
Other comprehensive income, Defined Benefit Pension Adjustment	0
Amounts reclassified from accumulated other comprehensive income, Defined Benefit Pension Adjustment	165	[1]
Balance, Defined Benefit Pension Adjustment	(21,379)
Balance, Total Accumulated Other Comprehensive (Loss) Income	(18,366)
Other Comprehensive loss	(2,034)
Amounts reclassified from accumulated other comprehensive income, Total Accumulated Other Comprehensive (Loss) Income	165	[1]
Balance, Total Accumulated Other Comprehensive (Loss) Income	$ (20,235)

[1] Amount represents amortization of actuarial losses, a component of net periodic benefit cost, net of $0.1 million tax benefit. See Note 7, Employer Sponsored Benefit Plans.