Fixed Assets (Detail) ¥ in Thousands, $ in Thousands	Dec. 31, 2015 USD ($)	Dec. 31, 2015 CNY (¥)	Dec. 31, 2014 CNY (¥)
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 2,880,267	¥ 18,657,795	¥ 14,584,658
Accumulated depreciation	(1,239,721)	(8,030,668)	(5,879,294)
Fixed assets, net	1,640,546	10,627,127	8,705,364
Computer equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	1,932,900	12,520,942	9,764,297
Office building
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	477,716	3,094,551	1,776,651
Office building and its related facility, machinery and equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	245,931	1,593,090	577,178
Vehicles
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	4,855	31,450	29,363
Office equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	66,866	433,144	342,452
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	46,668	302,304	311,076
Construction in Progress
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 105,331	¥ 682,314	¥ 1,783,641

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
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.14)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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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
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)
-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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-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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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)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6391035&loc=d3e2868-110229

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 13
-Subparagraph a
-Article 5

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
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