Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=6391035&loc=d3e2868-110229

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
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-Section S99
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-Subparagraph (SX 210.5-02.14)
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- Definition

Depreciation and amortization of property, plant and equipment directly related to goods produced and sold and services rendered by an entity during the reporting period.

+ References

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-Publisher FASB
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Amount before accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Section 50
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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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No definition available.

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Amount after accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business to produce goods and services and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(13))
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-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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-Publisher FASB
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Property and equipment, net (Details) ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016 CNY (¥)	Dec. 31, 2015 CNY (¥)	Dec. 31, 2014 CNY (¥)	Dec. 31, 2016 USD ($)
Property, Plant and Equipment [Line Items]
Property and equipment	¥ 155,663	¥ 87,071
Accumulated depreciation and amortization	(54,771)	(27,863)
Property and equipment, net	100,892	59,208		$ 14,531
Depreciation and amortization expenses	26,659	16,613	¥ 8,710
Electronic devices [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	48,432	32,729
Vehicle [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	3,209	2,718
Furniture and office equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	8,576	5,983
Leasehold improvement [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	84,121	45,641
Machinery and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	¥ 11,325