Future Minimum Payments Under Non-Cancelable Operating Leases with Initial Terms of One-Year or More (Detail) - Dec. 31, 2019 ¥ in Millions, $ in Millions	CNY (¥)	USD ($)
Future Minimum Payments Under Noncancelable Agreements For Bandwidth And Property Management Fees [Abstract]
2020	¥ 652	$ 94
2021	109	16
2022	77	11
2023	65	9
2024	63	9
Thereafter	63	9
Total Future minimum payments under non-cancelable agreements for bandwidth and property management fees	¥ 1,029	$ 148

Future minimum payments under non-cancelable agreements for bandwidth and property management fees.

No definition available.

Name:	bidu_FutureMinimumPaymentsUnderNoncancelableAgreementsForBandwidthAndPropertyManagementFees
Namespace Prefix:	bidu_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Future minimum payments under non-cancelable agreements for bandwidth and property management fees.

No definition available.

Name:	bidu_FutureMinimumPaymentsUnderNoncancelableAgreementsForBandwidthAndPropertyManagementFeesAbstract
Namespace Prefix:	bidu_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Future minimum payments under non-cancelable agreements for bandwidth and property management fees current.

No definition available.

Name:	bidu_FutureMinimumPaymentsUnderNoncancelableAgreementsForBandwidthAndPropertyManagementFeesCurrent
Namespace Prefix:	bidu_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Future minimum payments under non-cancelable agreements for bandwidth and property management fees five years.

No definition available.

Name:	bidu_FutureMinimumPaymentsUnderNoncancelableAgreementsForBandwidthAndPropertyManagementFeesFiveYears
Namespace Prefix:	bidu_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Future minimum payments under non-cancelable agreements for bandwidth and property management fees four years.

No definition available.

Name:	bidu_FutureMinimumPaymentsUnderNoncancelableAgreementsForBandwidthAndPropertyManagementFeesFourYears
Namespace Prefix:	bidu_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Future minimum payments under non-cancelable agreements for bandwidth and property management fees thereafter years.

No definition available.

Name:	bidu_FutureMinimumPaymentsUnderNoncancelableAgreementsForBandwidthAndPropertyManagementFeesThereafterYears
Namespace Prefix:	bidu_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Future minimum payments under non-cancelable agreements for bandwidth and property management fees three years.

No definition available.

Name:	bidu_FutureMinimumPaymentsUnderNoncancelableAgreementsForBandwidthAndPropertyManagementFeesThreeYears
Namespace Prefix:	bidu_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Future minimum payments under non-cancelable agreements for bandwidth and property management fees two years.

No definition available.

Name:	bidu_FutureMinimumPaymentsUnderNoncancelableAgreementsForBandwidthAndPropertyManagementFeesTwoYears
Namespace Prefix:	bidu_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant