Stockholders' equity - Schedule of Changes in Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jul. 31, 2026	Jul. 31, 2025	Jul. 31, 2026	Jul. 31, 2025
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	$ 2,047,395	$ 2,123,806	$ 2,107,196	$ 2,114,911
Other comprehensive income (loss) before reclassifications	12,141	(70)	20,556	(70)
Other comprehensive income (loss) before reclassifications, after tax	(37,322)	203	(63,219)	203
Amounts reclassified from AOCI, tax	(6)	0	42	0
Amounts reclassified from AOCI, after tax	22	0	(126)	0
Net change in AOCI, tax	12,135	(70)	20,598	(70)
Total other comprehensive income (loss)	(37,300)	203	(63,345)	203
Ending balance	1,990,110	2,146,421	1,990,110	2,146,421
Accumulated other comprehensive loss
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(31,752)	0	(5,707)	0
Total other comprehensive income (loss)	(37,300)	203	(63,345)	203
Ending balance	(69,052)	203	(69,052)	203
Change in unrealized losses on cash flow hedges
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(42,069)	0	(7,561)	0
Other comprehensive income (loss) before reclassifications, before tax	(49,463)	273	(83,775)	273
Amounts reclassified from AOCI, before tax	28	0	(168)	0
Net change in AOCI, before tax	(49,435)	273	(83,943)	273
Ending balance	(91,504)	273	(91,504)	273
Tax effect
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	10,317	0	1,854	0
Ending balance	$ 22,452	$ (70)	$ 22,452	$ (70)

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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