Tax Effect Allocated to Each Component of Other Comprehensive Income (Detail) ¥ in Thousands, $ in Thousands	12 Months Ended
Dec. 31, 2016 USD ($)	Dec. 31, 2016 CNY (¥)	Dec. 31, 2015 CNY (¥)	Dec. 31, 2014 CNY (¥)
Other Comprehensive Income (Loss), Tax [Abstract]
Unrealized gains on available-for-sale investments Unrealized holding gains (losses) during the year	$ (17,242)	¥ (119,708)	¥ (68,303)	¥ 1,680
Reclassified for gains realized	15,904	110,418	28,885	0
Net unrealized gains (losses)	(1,338)	(9,290)	(39,418)	1,680
Other comprehensive income (loss)	$ (1,338)	¥ (9,290)	¥ (39,418)	¥ 1,680

Amount of tax expense (benefit), after reclassification adjustments, of appreciation (loss) in value of unsold available-for-sale securities. Excludes amounts related to other than temporary impairment (OTTI) loss.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 10A
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-URI http://asc.fasb.org/extlink&oid=66004124&loc=SL7669646-108580

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Amount of tax expense (benefit) allocated to other comprehensive income (loss).

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Amount of tax expense (benefit) before reclassification adjustments of unrealized holding gain (loss) on available-for-sale securities.

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