Variable Interest Entities and Noncontrolling Interests - Non-redeemable noncontrolling interests (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2020	Mar. 31, 2019
Noncontrolling Interest [Line Items]
Non-redeemable noncontrolling interests, beginning of period		$ 762,777
Amounts attributable to noncontrolling interests		(233,944)	$ 42,382
Other comprehensive (income) loss attributable to noncontrolling interests		(33,058)	4,139
Non-redeemable noncontrolling interests, end of period		492,785	838,081
Watford Holdings Ltd
Noncontrolling Interest [Line Items]
Non-redeemable noncontrolling interests, beginning of period		762,777	791,560
Additional paid in capital attributable to noncontrolling interests		(123)	0
Repurchases attributable to non-redeemable noncontrolling interests	[1]	(2,867)	0
Amounts attributable to noncontrolling interests		(233,944)	42,382
Other comprehensive (income) loss attributable to noncontrolling interests		(33,058)	4,139
Non-redeemable noncontrolling interests, end of period		$ 492,785	$ 838,081
Noncontrolling shareholders | Common shares | Watford Holdings Ltd
Noncontrolling Interest [Line Items]
Noncontrolling interest, ownership percentage by noncontrolling owners		87.00%

[1] During 2020, Watford’s board of directors authorized the investment in Watford’s common shares through a share repurchase program.