Consolidated Statements of Changes in Shareholders' Equity - USD ($) $ in Thousands	Total	Treasury Shares (Series C Preferred Shares)	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Cumulative translation adjustment	Defined benefit pension liability	Unrealized gains (losses) on investments	Retained Earnings	Noncontrolling Interest (excludes redeemable noncontrolling interests)	Voting ordinary shares Ordinary Shares	Series C non-voting convertible ordinary shares Ordinary Shares	Series E non-voting convertible ordinary shares Ordinary Shares	Series C non-voting preferred shares Preferred Stock	Series D Preferred Shares Preferred Stock	Series E preferred perpetual shares Preferred Stock
Balance, beginning of year at Dec. 31, 2016			$ 1,380,109	$ (23,549)	$ (18,993)	$ (4,644)	$ 88	$ 1,847,550	$ 8,520	$ 16,175	$ 2,792	$ 405		$ 0	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issue of shares			450							35		0		0	0
Conversion of convertible securities										192	(192)
Issuance costs of preferred shares			0
Amortization of share-based compensation			14,508
Other comprehensive income (loss)	$ 35,960				9,413		2,352
Reclassification to earnings on disposal of subsidiary					20,751
Change in defined benefit pension liability	1,501					1,501
Net earnings (loss) attributable to Enstar Group Limited ordinary shareholders	311,458							331,799
Net loss (earnings) attributable to noncontrolling interest	(20,341)							(20,341)	722
Dividends on preferred shares								0
Change in redemption value of redeemable noncontrolling interests								(30,978)
Purchase of noncontrolling shareholders' interest in subsidiaries									0
Contribution of capital									22
Balance, end of year at Dec. 31, 2017		$ (421,559)	1,395,067	10,468	11,171	(3,143)	2,440	2,132,912	9,264	16,402	2,600	405	$ 389	0	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issue of shares			413,141							1,548		505		400,000	110,000
Conversion of convertible securities										0	0
Issuance costs of preferred shares			(14,643)
Amortization of share-based compensation			11,099
Other comprehensive income (loss)	(267)				(185)		(1,999)
Reclassification to earnings on disposal of subsidiary					0
Change in defined benefit pension liability	2,156					2,156
Net earnings (loss) attributable to Enstar Group Limited ordinary shareholders	(162,354)							(212,272)
Net loss (earnings) attributable to noncontrolling interest	62,051							62,051	2,743
Dividends on preferred shares								(12,133)
Change in redemption value of redeemable noncontrolling interests								7,554
Purchase of noncontrolling shareholders' interest in subsidiaries									0
Contribution of capital									49
Balance, end of year at Dec. 31, 2018	3,913,989	(421,559)	1,804,664	10,440	10,986	(987)	441	1,976,539	12,056	17,950	2,600	910	389	400,000	110,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issue of shares			583							52		0		0	0
Conversion of convertible securities										0	0
Issuance costs of preferred shares			0
Amortization of share-based compensation			31,531
Other comprehensive income (loss)	(3,384)				(2,438)		(873)
Reclassification to earnings on disposal of subsidiary					0
Change in defined benefit pension liability	42					42
Net earnings (loss) attributable to Enstar Group Limited ordinary shareholders	902,175							928,219
Net loss (earnings) attributable to noncontrolling interest	9,870							9,870	2,159
Dividends on preferred shares								(35,914)
Change in redemption value of redeemable noncontrolling interests								9,178
Purchase of noncontrolling shareholders' interest in subsidiaries									(47)
Contribution of capital									0
Balance, end of year at Dec. 31, 2019	$ 4,856,351	$ (421,559)	$ 1,836,778	$ 7,171	$ 8,548	$ (945)	$ (432)	$ 2,887,892	$ 14,168	$ 18,002	$ 2,600	$ 910	$ 389	$ 400,000	$ 110,000