Changes in accumulated other comprehensive income (loss) (Detail) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2014		Jun. 30, 2013
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance	$ (8,844)		$ (18,366)
Other Comprehensive loss	(3)		(998)
Amounts reclassified from accumulated other comprehensive income	223	[1]	331	[1]
Ending Balance	(8,624)		(19,033)
Accumulated Translation Adjustment [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance	6,128		3,178
Other Comprehensive loss	(3)		(998)
Amounts reclassified from accumulated other comprehensive income	0		0
Ending Balance	6,125		2,180
Accumulated Defined Benefit Plans Adjustment [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance	(14,972)		(21,544)
Other Comprehensive loss	0		0
Amounts reclassified from accumulated other comprehensive income	223	[1]	331	[1]
Ending Balance	$ (14,749)		$ (21,213)

[1] Amount represents amortization of actuarial losses, a component of net periodic benefit cost. This amount was $0.1 million net of $0.1 million tax benefit and $0.2 million net of a $0.1 million tax benefit for the quarters ended June 30, 2014 and 2013, respectively. This amount was $0.2 million net of $0.1 million tax benefit and $0.3 million net of a $0.2 million tax benefit for the six months ended ended June 30, 2014 and 2013, respectively. See Note 8, Employer Sponsored Benefit Plans.