Share-Based Awards - Additional Information (Detail) - USD ($) $ in Thousands				12 Months Ended
	Jun. 09, 2020	Aug. 08, 2019	Feb. 21, 2019	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost expected recognition period				2 years 7 months 6 days
Share-based compensation				$ 317,192	$ 197,550	$ 198,902
Chief Executive Officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Accelerated vesting period from departure date			18 months
Exercisable period from final date			90 days
Share-based compensation						26,400
Minimum | Chief Executive Officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility			46.00%
Risk-free interest rate			2.47%
Weighted-average expected life			3 years 10 months 2 days
Maximum | Chief Executive Officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility			47.00%
Risk-free interest rate			2.49%
Weighted-average expected life			5 years 3 months
Zillow Group, Inc. 2020 Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for future issuance (in shares)	12,400,000
Increase in number of shares of common and capital stock available for issuance, percentage	5.00%
Exercise price per share fixed	100.00%
2019 Equity Inducement Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for future issuance (in shares)		10,000,000
Exercise price per share fixed		100.00%
Option Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized cost of unvested share-based compensation awards				518,200
Total intrinsic value of shares				309,800	564,300	51,100
Fair value of options				$ 172,500	$ 85,200	$ 100,100
Option Awards | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility				52.00%	45.00%	45.00%
Risk-free interest rate				0.57%	0.22%	1.60%
Weighted-average expected life				4 years 6 months	4 years 6 months	4 years 9 months
Option Awards | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility				58.00%	52.00%	47.00%
Risk-free interest rate				1.15%	0.93%	2.53%
Weighted-average expected life				5 years 9 months	5 years 6 months	5 years 3 months
Option Awards | Zillow Group, Inc. 2020 Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share based compensation arrangement by share based payment, award maximum exercisable period				12 months
Expiration period				10 years
Vesting percentage				25.00%
Option Awards | Zillow Group, Inc. 2020 Incentive Plan | Vesting, Option One
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period				12 months
Option Awards | Zillow Group, Inc. 2020 Incentive Plan | Vesting, Option Two
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period				3 years
Option Awards | Zillow Group, Inc. 2020 Incentive Plan | Vesting, Option Three
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period				4 years
Option Awards | 2019 Equity Inducement Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share based compensation arrangement by share based payment, award maximum exercisable period				12 months
Expiration period				10 years
Vesting percentage				25.00%
Share based compensation arrangement by share based payment, award minimum exercisable period				3 months
Option Awards | 2019 Equity Inducement Plan | Vesting, Option One
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period				12 months
Option Awards | 2019 Equity Inducement Plan | Vesting, Option Two
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period				3 years
Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost expected recognition period				2 years 6 months
Total fair value of awards vested				$ 152,100	$ 124,800	$ 89,900
Total unrecognized compensation cost				$ 374,100
Restricted Stock Units | Zillow Group, Inc. 2020 Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage				25.00%
Restricted Stock Units | Zillow Group, Inc. 2020 Incentive Plan | Vesting, Option One
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period				12 months
Restricted Stock Units | Zillow Group, Inc. 2020 Incentive Plan | Vesting, Option Two
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period				3 years
Restricted Stock Units | Zillow Group, Inc. 2020 Incentive Plan | Vesting, Option Three
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period				4 years
Restricted Stock Units | 2019 Equity Inducement Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage				25.00%
Restricted Stock Units | 2019 Equity Inducement Plan | Vesting, Option One
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period				12 months
Restricted Stock Units | 2019 Equity Inducement Plan | Vesting, Option Two
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period				3 years