Restructuring Expenses - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	1 Months Ended	3 Months Ended		6 Months Ended
	Feb. 29, 2012	Jun. 30, 2012	Mar. 31, 2012	Jun. 30, 2013
Restructuring Cost and Reserve [Line Items]
Lease/rental terminations charges for restructuring				$ 3.5
Annualized savings	7.0
One-time employee termination and other costs			0.3
Restructuring charges for reduction workforce		0.1
Maximum [Member]
Restructuring Cost and Reserve [Line Items]
Reduction in company's worldwide workforce				30.00%
Special charges for restructuring plan				6.8
Severance costs for affected employees				1.5
Other restructuring related costs				1.8
Estimated restructuring cash expenditures				3.1
Percentage reduction of headcount	8.00%
Minimum [Member]
Restructuring Cost and Reserve [Line Items]
Reduction in company's worldwide workforce				25.00%
Special charges for restructuring plan				5.0
Severance costs for affected employees				0.9
Other restructuring related costs				0.6
Estimated restructuring cash expenditures				$ 2.7
Percentage reduction of headcount	7.00%