Long-Lived Assets - Textbook Library, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Textbook library		$ 33,980
Less accumulated depreciation		(31,405)
Textbook library, net	$ 0	$ 2,575

Carrying amount as of the balance sheet date of amounts paid for textbooks which met the criteria for capitalization, net of related accumulated depreciation, which is expected to be used beyond one year.

No definition available.

Name:	chgg_TextbookLibraryNet
Namespace Prefix:	chgg_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant