Income Taxes (Effective Income Tax Rate Reconciliation) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Corporate Income Tax Rate [Line Items]
Income before income tax expense	$ 286,494	$ 124,019	$ 62,695
Income tax expense at the statutory income tax rate	71,624	31,005	15,674
Permanent differences	5,506	1,663	870
Effect of different income tax calculation method required by tax bureau	(5)	48	67
Effect of income tax holiday and preferential tax rates	(58,529)	(43,460)	(17,844)
Changes in valuation allowance	7,855	3,758	420
Total income tax expense	51,425us-gaap_IncomeTaxExpenseBenefit	23,423us-gaap_IncomeTaxExpenseBenefit	11,379us-gaap_IncomeTaxExpenseBenefit
PRC [Member]
Corporate Income Tax Rate [Line Items]
PRC statutory income tax rate (in percentage)	25.00%	25.00%	25.00%
Cayman Islands and other jurisdictions [Member]
Corporate Income Tax Rate [Line Items]
Effect of tax exempt status in Cayman Islands and other jurisdictions	24,701	30,241	12,217
Hong Kong [Member]
Corporate Income Tax Rate [Line Items]
Effect of different income tax rate in Hong Kong	$ 273	$ 168	$ (25)

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Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic statutory income tax rates to pretax income (loss) from continuing operations attributable to applying different income tax calculation method.

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Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

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Sum of operating profit and nonoperating income or expense before Income or Loss from equity method investments, income taxes, extraordinary items, and noncontrolling interest.

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Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to increase (decrease) in the valuation allowance for deferred tax assets.

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The amount of income tax expense or benefit for the period computed by applying the domestic federal statutory tax rates to pretax income from continuing operations.

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Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to income exempt from income tax because of a tax holiday.

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