Principal Accounting Policies - Summary of ASC606, Revenue from Contracts with Customers (Details) ¥ in Millions, $ in Millions	12 Months Ended
Dec. 31, 2019 CNY (¥)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 CNY (¥)
Accounting Policies [Abstract]
Sales taxes and related surcharges recorded as a reduction of revenues	¥ 125.5	$ 18.0	¥ 123.0
Revenues from advertising-for-advertising barter transactions	7.4	1.1	4.7
Expenses from advertising-for-advertising barter transactions	¥ 7.4	$ 1.1	¥ 4.8

The amount of excise and sales taxes included in sales and revenues, which are then deducted as a cost of sales. Includes excise taxes, which are applied to specific types of transactions or items (such as gasoline or alcohol); and sales, use and value added taxes, which are applied to a broad class of revenue-producing transactions involving a wide range of goods and services.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(1))
-URI http://asc.fasb.org/extlink&oid=116634182&loc=SL114868664-224227

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration