Variable Interest Entity and Noncontrolling Interests - Non-redeemable noncontrolling interest (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Noncontrolling Interest [Line Items]
Non-redeemable noncontrolling interest, beginning of year	$ 823,007	$ 762,777
Amounts attributable to nonredeemable noncontrolling interests	(78,314)	(53,076)	$ (40,072)
Other comprehensive (income) loss attributable to noncontrolling interests	13,984	(9,062)	(9,130)
Non-redeemable noncontrolling interest, end of year	0	$ 823,007	762,777
Somers Holdings Ltd.
Noncontrolling Interest [Line Items]
Noncontrolling interest, ownership percentage by noncontrolling owners		87.00%
Somers Holdings Ltd. \| Noncontrolling Interest
Noncontrolling Interest [Line Items]
Non-redeemable noncontrolling interest, beginning of year	823,007	$ 762,777
Impact of deconsolidation of Somers	(918,874)	0
Additional paid in capital attributable to noncontrolling interests	22,113	1,334
Repurchases attributable to non-redeemable noncontrolling interests	0	(2,867)
Amounts attributable to nonredeemable noncontrolling interests	78,314	53,076
Other Amounts Attributable to Noncontrolling Interests	0	(375)
Other comprehensive (income) loss attributable to noncontrolling interests	(4,560)	9,062
Non-redeemable noncontrolling interest, end of year	$ 0	$ 823,007	$ 762,777

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