INCOME TAXES - Operating and capital loss carryforwards and tax credits (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Operating Loss And Tax Credit Carryforwards [Line Items]
Operating and capital loss carryforwards	$ 85,358	$ 80,008
Singapore
Operating Loss And Tax Credit Carryforwards [Line Items]
Operating loss carryforwards	76,287	110,504
United Kingdom
Operating Loss And Tax Credit Carryforwards [Line Items]
Operating loss carryforwards	308,491	357,226
Tax credit	2,372	8,756
Ireland
Operating Loss And Tax Credit Carryforwards [Line Items]
Operating loss carryforwards	11,850	404
Tax credit	338	2,386
Ireland | Capital loss carryforward
Operating Loss And Tax Credit Carryforwards [Line Items]
Capital loss carryforwards	716	716
Switzerland
Operating Loss And Tax Credit Carryforwards [Line Items]
Operating loss carryforwards	15,989	0
Belgium
Operating Loss And Tax Credit Carryforwards [Line Items]
Operating loss carryforwards	0	1,850
Lloyd's
Operating Loss And Tax Credit Carryforwards [Line Items]
Operating and capital loss carryforwards	0	39,000
Lloyd's | United Kingdom
Operating Loss And Tax Credit Carryforwards [Line Items]
Operating loss carryforwards	$ 0	$ 206,000