Stock-Based Compensation - Summary of Restricted Stock Unit and PSU Activity (Detail)	3 Months Ended
	Mar. 31, 2023 $ / shares shares
Time-Based Restricted Stock Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Unvested shares of restricted stock and restricted stock units outstanding at beginning of period | shares	479,100
Restricted Stock Awards and restricted stock units, Granted | shares	214,400
Restricted Stock Awards and restricted stock units, Vested | shares	(1,400)
Restricted Stock Awards and restricted stock units, Forfeited | shares	(22,300)
Unvested shares of restricted stock and restricted stock units outstanding at end of period | shares	669,800
Unvested shares of restricted stock and restricted stock units outstanding, Weighted Average Grant Date Fair Value Per Share, at beginning of period | $ / shares	$ 315.04
Granted, Weighted Average Grant Date Fair Value Per Share | $ / shares	337.44
Vested, Weighted Average Grant Date Fair Value Per Share | $ / shares	234.93
Forfeited, Weighted Average Grant Date Fair Value Per Share | $ / shares	330.68
Unvested shares of restricted stock and restricted stock units outstanding, Weighted Average Grant Date Fair Value Per Share, at end of period | $ / shares	$ 321.86
Market-Based Restricted Stock Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Unvested shares of restricted stock and restricted stock units outstanding at beginning of period | shares	1,677,000.0
Restricted Stock Awards and restricted stock units, Granted | shares	87,600
Restricted Stock Awards and restricted stock units, Forfeited | shares	(5,600)
Unvested shares of restricted stock and restricted stock units outstanding at end of period | shares	1,759,000.0
Unvested shares of restricted stock and restricted stock units outstanding, Weighted Average Grant Date Fair Value Per Share, at beginning of period | $ / shares	$ 116.36
Granted, Weighted Average Grant Date Fair Value Per Share | $ / shares	316.12
Forfeited, Weighted Average Grant Date Fair Value Per Share | $ / shares	296.37
Unvested shares of restricted stock and restricted stock units outstanding, Weighted Average Grant Date Fair Value Per Share, at end of period | $ / shares	$ 125.74
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Unvested shares of restricted stock and restricted stock units outstanding at beginning of period | shares	500
Unvested shares of restricted stock and restricted stock units outstanding at end of period | shares	500	[1]
Unvested shares of restricted stock and restricted stock units outstanding, Weighted Average Grant Date Fair Value Per Share, at beginning of period | $ / shares	$ 377.01
Unvested shares of restricted stock and restricted stock units outstanding, Weighted Average Grant Date Fair Value Per Share, at end of period | $ / shares	$ 377.01	[1]
Performance-Based Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Unvested shares of restricted stock and restricted stock units outstanding at beginning of period | shares	77,800
Restricted Stock Awards and restricted stock units, Vested | shares	(5,200)
Restricted Stock Awards and restricted stock units, Forfeited | shares	(3,500)
Unvested shares of restricted stock and restricted stock units outstanding at end of period | shares	69,100	[1]
Unvested shares of restricted stock and restricted stock units outstanding, Weighted Average Grant Date Fair Value Per Share, at beginning of period | $ / shares	$ 409.13
Vested, Weighted Average Grant Date Fair Value Per Share | $ / shares	526.66
Forfeited, Weighted Average Grant Date Fair Value Per Share | $ / shares	526.66
Unvested shares of restricted stock and restricted stock units outstanding, Weighted Average Grant Date Fair Value Per Share, at end of period | $ / shares	$ 394.29	[1]

[1] A maximum of 172,680 shares could be delivered upon settlement of PSUs based upon Paycom’s Relative TSR over the applicable performance periods.