Variable interest entities - Narrative (Details)	3 Months Ended
	Mar. 31, 2024
Equity share capital | VIE (“Philippines Business”)
Variable Interest Entity [Line Items]
Subsidiary, ownership percentage, noncontrolling owner	60.00%
Equity share capital | Variable interest entity, primary beneficiary
Variable Interest Entity [Line Items]
Variable interest entity, qualitative or quantitative information, ownership percentage	40.00%
Share of earnings and distributions | VIE (“Philippines Business”)
Variable Interest Entity [Line Items]
Subsidiary, ownership percentage, noncontrolling owner	45.00%
Share of earnings and distributions | Variable interest entity, primary beneficiary
Variable Interest Entity [Line Items]
Variable interest entity, qualitative or quantitative information, ownership percentage	55.00%