Acquired Intangible Assets, Capitalized Software Development Costs, and Goodwill - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended			3 Months Ended
	Jun. 30, 2012	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013
Finite Lived Intangible Assets [Line Items]
Capitalized software development costs		$ 1,712	$ 1,987	$ 1,890
Goodwill impairment method for determination of fair value description		Our discounted cash flow models are based on our most recent long-range forecast and, for years beyond the forecast, we estimated terminal values based on perpetual cash flow growth rates ranging from 2.5% to 4.0%. The models reflect management’s expectation of future market conditions and expected levels of financial performance for our reporting units, as well as discount rates and estimated terminal values that would be used by market participants in an arms-length transaction. Business operational risks which could impact profits are detailed in our “Risk Factors” disclosures. Discount rates used were intended to reflect the risks inherent in the future cash flows of the respective reporting units and were between 13% and 15%
Goodwill		104,241	104,241	112,450	104,241
Impairment charge related to goodwill	86,332		8,209
Minimum | Discounted Cash Flow Approach
Finite Lived Intangible Assets [Line Items]
Discounted rate used to estimate terminal value		13.00%
Growth rate used to estimate terminal value		2.50%
Minimum | Market Comparable Approach
Finite Lived Intangible Assets [Line Items]
Adjusted EBITDA multiples used to evaluate fair value of reporting units		5.00
Revenue multiples used to evaluate fair value of reporting units		0.400
Maximum | Discounted Cash Flow Approach
Finite Lived Intangible Assets [Line Items]
Discounted rate used to estimate terminal value		15.00%
Growth rate used to estimate terminal value		4.00%
Maximum | Market Comparable Approach
Finite Lived Intangible Assets [Line Items]
Adjusted EBITDA multiples used to evaluate fair value of reporting units		13.00
Revenue multiples used to evaluate fair value of reporting units		1.50
Platforms and applications
Finite Lived Intangible Assets [Line Items]
Impairment charge related to acquired intangible assets			599
Impairment charge related to capitalized software development			9,270
Goodwill		27,912	27,912	36,121	27,912
Goodwill, fair value			27,912		27,912
Impairment charge related to goodwill			8,209		8,209
Navigation reporting Unit
Finite Lived Intangible Assets [Line Items]
Impairment charge related to acquired intangible assets				13,964
Impairment charge related to capitalized software development				12,420
Impairment charge related to goodwill				$ 86,332
Acquired intangible assets including customer lists and other
Finite Lived Intangible Assets [Line Items]
Estimated weighted average amortization period		3 years 10 months 24 days