Segment reporting - Summary of Sub-Unit Information by Revenue (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
Segment Reporting [Line Items]
Total revenue	$ 937.7	$ 659.5	$ 1,606.5	$ 1,153.5
Reportable Segment [Member]
Segment Reporting [Line Items]
Total revenue	937.7	659.5	1,606.5	1,153.5
Equipment revenue [Member]
Segment Reporting [Line Items]
Total revenue	569.3	354.1	891.8	564.3
Equipment revenue [Member] \| Reportable Segment [Member]
Segment Reporting [Line Items]
Total revenue	569.3	354.1	891.8	564.3
Equipment revenue [Member] \| Reportable Segment [Member] \| Data Center [Member]
Segment Reporting [Line Items]
Total revenue	232.4	118.0	339.4	170.3
Equipment revenue [Member] \| Reportable Segment [Member] \| Power Solutions [Member]
Segment Reporting [Line Items]
Total revenue	273.6	181.5	441.7	295.8
Equipment revenue [Member] \| Reportable Segment [Member] \| Compression [Member]
Segment Reporting [Line Items]
Total revenue	63.3	54.6	110.7	98.2
Total service revenue
Segment Reporting [Line Items]
Total revenue	368.4	305.4	714.7	589.2
Total service revenue \| Reportable Segment [Member]
Segment Reporting [Line Items]
Total revenue	368.4	305.4	714.7	589.2
Total service revenue \| Reportable Segment [Member] \| Transactional [Member]
Segment Reporting [Line Items]
Total revenue	236.1	192.8	442.3	364.8
Total service revenue \| Reportable Segment [Member] \| Contractual [Member]
Segment Reporting [Line Items]
Total revenue	$ 132.3	$ 112.6	$ 272.4	$ 224.4