Variable Interest Entity and Noncontrolling Interests - Non-redeemable noncontrolling interest (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Noncontrolling Interest [Line Items]
Non-redeemable noncontrolling interest, beginning of year	$ 791,560	$ 843,411
Amounts attributable to nonredeemable noncontrolling interests	(40,072)	48,507	$ 7,913
Non-redeemable noncontrolling interest, end of year	762,777	791,560	843,411
Watford Holdings Ltd \| Noncontrolling Interest
Noncontrolling Interest [Line Items]
Non-redeemable noncontrolling interest, beginning of year	791,560	843,411
Additional paid in capital attributable to non-redeemable noncontrolling interests	(2,929)	0
Repurchases attributable to non-redeemable noncontrolling interests (1)	(75,056)	0
Amounts attributable to nonredeemable noncontrolling interests	40,072	(48,507)
Other comprehensive (income) loss attributable to non-redeemable noncontrolling interests	9,130	(3,344)
Non-redeemable noncontrolling interest, end of year	$ 762,777	$ 791,560	$ 843,411
Common shares \| Watford Holdings Ltd \| Noncontrolling Interest
Noncontrolling Interest [Line Items]
Noncontrolling interest, ownership percentage by noncontrolling owners	87.00%

Minority Interest Foreign Currency Translation Adjustments

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Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which is directly or indirectly attributable to that ownership interest in subsidiary equity which is not attributable to the parent (that is, noncontrolling interest, previously referred to as minority interest).

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Decrease in noncontrolling interest (for example, but not limited to, redeeming or purchasing the interests of noncontrolling shareholders, issuance of shares (interests) by the non-wholly owned subsidiary to the parent entity for other than cash, and a buyback of shares (interest) by the non-wholly owned subsidiary from the noncontrolling interests).

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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The equity interest of noncontrolling shareholders, partners or other equity holders in consolidated entity.

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Portion of net income (loss) attributable to nonredeemable noncontrolling interest.

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Amount of increase in noncontrolling interest from subsidiary issuance of equity interests to noncontrolling interest holders.

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