Goodwill and intangible assets - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2026	Dec. 31, 2025	Dec. 31, 2024
Indefinite-Lived Intangible Assets [Line Items]
Goodwill	$ 30,193	$ 30,193	$ 55,697
Goodwill impairment	0	25,504
Asset Management
Indefinite-Lived Intangible Assets [Line Items]
Goodwill	1,000	1,000
Insurance Solutions
Indefinite-Lived Intangible Assets [Line Items]
Goodwill	30,193	30,193
Insurance Solutions | Multi Year Guaranteed Annuities
Indefinite-Lived Intangible Assets [Line Items]
Goodwill	30,193	30,193	30,193
Goodwill impairment		0
Insurance Solutions | Long-Term Care
Indefinite-Lived Intangible Assets [Line Items]
Goodwill	$ 0	0	$ 25,504
Goodwill impairment		$ 25,504