Schedule II - Narrative (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Condensed Financial Statements, Captions [Line Items]
Dividends and return of capital from subsidiaries, non-cash									$ 0	$ 0	$ 31,600,000
Contributions to subsidiaries, non-cash									0	414,800,000	148,100,000
Retained earnings	$ 2,887,892,000				$ 1,976,539,000				2,887,892,000	1,976,539,000
Net earnings attributable to Enstar Group Limited	193,839,000	$ 117,743,000	$ 231,842,000	$ 358,751,000	(113,423,000)	$ (15,965,000)	$ 8,244,000	$ (41,210,000)	902,175,000	(162,354,000)	311,458,000
Limited Parental Guarantee
Condensed Financial Statements, Captions [Line Items]
Total parental guarantees	1,031,500,000				614,500,000				1,031,500,000	614,500,000
Enstar Group Limited
Condensed Financial Statements, Captions [Line Items]
Interest paid									46,500,000	25,100,000	17,600,000
Retained earnings	2,887,892,000				$ 1,976,539,000				2,887,892,000	1,976,539,000
Increase in retained earnings									911,400,000
Net earnings attributable to Enstar Group Limited									902,175,000	$ (162,354,000)	$ 311,458,000
Enstar Group Limited | Limited Parental Guarantee
Condensed Financial Statements, Captions [Line Items]
Total parental guarantees	1,031,500,000								1,031,500,000
Letters of Credit | FAL Facility | Enstar Group Limited | Limited Parental Guarantee
Condensed Financial Statements, Captions [Line Items]
Total parental guarantees	$ 252,000,000.0								$ 252,000,000.0