Fair Value Measurements, Financial Instruments, and Credit Risk - Additional Information (Detail)	3 Months Ended		6 Months Ended			1 Months Ended	3 Months Ended							3 Months Ended			3 Months Ended		6 Months Ended
	Jun. 30, 2013 USD ($)	Jun. 30, 2012 USD ($)	Jun. 30, 2013 USD ($)	Jun. 30, 2012 USD ($)	Dec. 31, 2012 USD ($)	Jun. 30, 2011 Interest Rate Swap Agreement [Member] USD ($)	Mar. 31, 2013 Interest Rate Swap Agreement [Member] USD ($)	Mar. 31, 2012 Interest Rate Swap Agreement [Member] USD ($)	Jun. 30, 2013 Fair Value Hedges [Member] Settlement date of September 9, 2013 [Member] CAD	Jun. 30, 2013 Fair Value Hedges [Member] Settlement date of October 8, 2013 [Member] CAD	Jun. 30, 2013 Net Investment Hedges [Member] USD ($)	Jun. 30, 2013 Net Investment Hedges [Member] EUR (€)	Jun. 30, 2012 Net Investment Hedges [Member] USD ($)	Jun. 30, 2013 Net Investment Hedges [Member] Minimum [Member]	Dec. 31, 2012 Net Investment Hedges [Member] Minimum [Member] EUR (€)	Dec. 31, 2012 Net Investment Hedges [Member] Maximum [Member] EUR (€)	Jun. 30, 2013 Foreign Currency Hedges [Member] USD ($)	Jun. 30, 2012 Foreign Currency Hedges [Member] USD ($)	Jun. 30, 2013 Foreign Currency Hedges [Member] USD ($)	Jun. 30, 2012 Foreign Currency Hedges [Member] USD ($)
Derivative [Line Items]
Interest rate swap agreement, notional amount						$ 75,000,000			2,500,000	1,600,000		€ 11,600,000			€ 50,000,000	€ 100,000,000
Agreement effective date						Jul. 15, 2011
Agreement maturity date						Jun. 15, 2014
Interest expense recognized							700,000
Unrealized gain (loss) in accumulated other comprehensive income (loss)	0		0		(837,000)			100,000
Loss on effective portion forward contracts qualified for hedge	100,000	200,000	100,000	200,000
Gain on effective portion forward contracts qualified for hedge	100,000	200,000	100,000	200,000
Forward contracts, expiration period														30 days
Gain in accumulated other comprehensive income (loss) related to effective portion of settlement of contracts											0		1,800,000
Aggregate gain (loss) on settlement of hedges																	$ 60,000	$ 30,000	$ 1,800,000	$ 1,100,000