Basic and Diluted Net Income Per Share - Summary of Basic and Diluted Net Income Per Share of Class A and Class B Common Stock (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Numerator:
Allocation of net income attributable to Guardian Pharmacy Services, Inc.	$ 13,295	$ 9,448
Numerator:
Allocation of net income attributable to Guardian Pharmacy Services, Inc.	13,295	9,448
Common Class A [Member]
Numerator:
Allocation of net income attributable to Guardian Pharmacy Services, Inc.	$ 7,738	$ 1,490
Denominator:
Weighted average number of shares of Class A and Class B common stock outstanding	36,855	9,787
Basic net income per share attributable to common stockholders	$ 0.21	$ 0.15
Numerator:
Allocation of net income attributable to Guardian Pharmacy Services, Inc.	$ 7,738	$ 1,490
Denominator:
Number of shares used in basic computation	36,855	9,787
Weighted average shares of Class A and Class B common stock outstanding used to calculate diluted net income per share	37,071	9,924
Diluted net income per share attributable to common stockholders	$ 0.21	$ 0.15
Common Class B [Member]
Numerator:
Allocation of net income attributable to Guardian Pharmacy Services, Inc.	$ 5,557	$ 7,958
Denominator:
Weighted average number of shares of Class A and Class B common stock outstanding	26,466	52,256
Basic net income per share attributable to common stockholders	$ 0.21	$ 0.15
Numerator:
Allocation of net income attributable to Guardian Pharmacy Services, Inc.	$ 5,557	$ 7,958
Denominator:
Number of shares used in basic computation	26,466	52,256
Weighted average shares of Class A and Class B common stock outstanding used to calculate diluted net income per share	26,621	52,989
Diluted net income per share attributable to common stockholders	$ 0.21	$ 0.15
Restricted Stock [Member] | Common Class A [Member]
Denominator:
Dilutive Restricted Stock Units and Class A and B Common Stock	216
Restricted Stock [Member] | Common Class B [Member]
Denominator:
Dilutive Restricted Stock Units and Class A and B Common Stock	155