Income Taxes - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Taxes [Line Items]
Amount of prepaid tax amortized to income tax expense	$ 150,000
Deferred tax assets valuation allowance increase (decrease)	80,800,000	(70,500,000)	28,500,000
Interest expense	65,000
Increase in liability for uncertain tax positions	24,700,000
Deferred tax assets valuation allowance decreased	19,200,000
Long term liability relating to uncertain tax positions recognized	2,000,000
Tax benefit that would be recognized if unrecognized tax benefits were realized and not subject to valuation allowances	21,200,000
Federal
Income Taxes [Line Items]
Net operating loss carryforwards related to stock-based compensation tax deductions	$ 50,300,000