Income Taxes (Components of Deferred Tax Assets and Liabilities) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Current deferred tax assets
Accrued payroll	$ 5,141	$ 2,889
Provision of allowance for doubtful accounts	478	92
Deferred revenue-current	660	306
Less: Valuation allowance	(1,435)	(158)
Current deferred tax assets, net	4,844us-gaap_DeferredTaxAssetsNetCurrent	3,129us-gaap_DeferredTaxAssetsNetCurrent
Noncurrent deferred tax assets
Deferred revenue-noncurrent	339	383
Intangible assets	953	266
Fixed assets	100	66
Subsidy income	270	231
Net operating loss carry forwards	9,193	4,592
Promotion fee	13,894	0
Unrealized loss on available-for-sale investments	2,462	0
Less: Valuation allowance	(10,846)	(4,592)
Noncurrent deferred tax assets, net	16,365us-gaap_DeferredTaxAssetsNetNoncurrent	946us-gaap_DeferredTaxAssetsNetNoncurrent
Noncurrent deferred tax liabilities
Acquired intangible assets	8,159	2,676
Unrealized gain on available-for-sale investments	357	0
Noncurrent deferred tax liabilities	$ 8,516	$ 2,676

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from promotion fee.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from subsidy income, which is expected to be realized or consumed after one year (or the normal operating cycle, if longer).

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from intangible assets including goodwill.

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Amount after allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards expected to be realized or consumed within one year or operating cycle, if longer.

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Amount after allocation of valuation allowances of noncurrent deferred tax asset attributable to deductible temporary differences and carryforwards. Noncurrent assets are expected to be realized or consumed after one year (or the normal operating cycle, if longer).

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from property, plant, and equipment.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from compensation and benefits costs.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from the allowance for doubtful accounts.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from unrealized losses on available-for-sale securities.

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Amount of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards expected to be realized or consumed within one year or operating cycle, if longer.

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Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized expected to be realized or consumed after one year (or the normal operating cycle, if longer).

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Amount of deferred tax liability attributable to taxable temporary differences from intangible assets other than goodwill.

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Amount of deferred tax liability attributable to taxable temporary differences, net of deferred tax asset attributable to deductible temporary differences and carryforwards net of valuation allowances expected to be realized or consumed after one year (or the normal operating cycle, if longer).

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