Discontinued operations - Narrative (Details) - USD ($) $ in Thousands			12 Months Ended
	Dec. 31, 2024	Dec. 30, 2024	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
American Savings Bank (ASB) | ASB Hawaii, Inc
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Minority ownership percentage	9.90%	9.90%	9.90%
Noncontrolling ownership interest	$ 44,600		$ 44,600
Discontinued Operations, Disposed of by Sale | American Savings Bank (ASB)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Ownership percentage disposed		90.10%
Consideration amount		$ 405,500
Net loss on sale	(115,803)
Income tax benefit	2,390		2,390	$ 0	$ 0
Deferred tax asset, valuation allowance	$ 66,430
Noncash transaction			$ 507,800