Retirement Savings Plan - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Defined Benefit Plan Disclosure [Line Items]
Employer matching contributions vesting period	2 years
United States [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer matching contributions	$ 1,000,000	$ 1,200,000	$ 1,100,000
Canada [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer matching contributions	$ 157,000	$ 232,000	$ 280,000