Revenue - Summary of Disaggregation of Revenue (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Disaggregation Of Revenue [Line Items]
Total revenue	$ 257.2	$ 204.4	$ 742.1	$ 619.7
Cloud Dayforce Recurring [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	160.3	122.7	456.2	369.3
Cloud Dayforce Professional Services and Other [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	38.4	35.1	113.2	108.8
Cloud Dayforce Revenue [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	198.7	157.8	569.4	478.1
Cloud Powerpay Recurring [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	20.7	18.6	61.5	56.6
Cloud Powerpay Professional Services and Other [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	0.2	0.3	0.8	0.8
Cloud Powerpay Revenue [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	20.9	18.9	62.3	57.4
Cloud Powerpay Revenue [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	219.6	176.7	631.7	535.5
Bureau Recurring Revenue [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	34.0	26.8	101.4	82.8
Bureau Professional Services and Other Revenue [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	3.6	0.9	9.0	1.4
Bureau Revenue [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	$ 37.6	$ 27.7	$ 110.4	$ 84.2