Cash, Cash Equivalents, and Marketable Securities (Parenthetical) (Detail) (USD $) In Billions, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Cash, cash equivalents and marketable securities [Line Items]
Cash collateral received from securities lending program	$ 1.3	$ 1.6

Cash collateral received from security lending program that is invested in reverse repurchase agreements maturing within three months.

No definition available.

Name:	goog_CashCollateralReceived
Namespace Prefix:	goog_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant