Acquisitions - Pro Forma Condensed Combined Statement of Earnings (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Total income	$ 217,633	$ 268,067	$ 256,398	$ 287,299	$ 223,019	$ 212,436	$ 296,485	$ 127,577	$ 1,029,397	$ 859,517	$ 416,570
Total expenses									(819,056)	(632,281)	(192,748)
Net earnings (loss) attributable to noncontrolling interest	(19,216)	(3,041)	3,662	8,645	12,378	(5,232)	2,516	3,825	(9,950)	13,487	15,218
NET EARNINGS ATTRIBUTABLE TO ENSTAR GROUP LIMITED	$ 111,857	$ 49,042	$ 14,545	$ 44,847	$ 105,940	$ 26,429	$ 51,793	$ 29,587	220,291	213,749	208,604
Sussex Insurance Company, National Suisse Assurance S.A., and Wilton Relife Settlements
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Total income									1,106,558	1,175,187
Total expenses									(903,676)	(1,058,312)
Total noncontrolling interest									9,950	(13,487)
Net earnings (loss)									212,832	103,388
Sussex Insurance Company, National Suisse Assurance S.A., and Wilton Relife Settlements | Proforma Adjustments
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Total income									9,494	(14,557)
Total expenses									5,894	(3,026)
Total noncontrolling interest									0	0
Net earnings (loss)									15,388	(17,583)
StarStone
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Total income										1,004,864	1,042,886
Total expenses										(774,090)	(885,770)
Total noncontrolling interest										(14,938)	12,145
Net earnings (loss)										215,836	169,261
StarStone | Proforma Adjustments
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Total income										(1,846)	(7,384)
Total expenses										3,670	14,678
Total noncontrolling interest										(1,451)	27,363
Net earnings (loss)										373	34,657
Sussex Insurance Company
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Total income									29,990	267,939
Total expenses									(39,860)	(360,018)
Net earnings (loss) attributable to noncontrolling interest									0	0
NET EARNINGS ATTRIBUTABLE TO ENSTAR GROUP LIMITED									(9,870)	(92,079)
Alpha
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Total income									31,884	44,910
Total expenses									(47,026)	(52,103)
Net earnings (loss) attributable to noncontrolling interest									0	0
NET EARNINGS ATTRIBUTABLE TO ENSTAR GROUP LIMITED									(15,142)	(7,193)
Wilton Relife Settlements
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Total income									5,793	17,378
Total expenses									(3,628)	(10,884)
Net earnings (loss) attributable to noncontrolling interest									0	0
NET EARNINGS ATTRIBUTABLE TO ENSTAR GROUP LIMITED									$ 2,165	6,494
StarStone
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Total income										147,193	633,700
Total expenses										(145,479)	(707,700)
Net earnings (loss) attributable to noncontrolling interest										0	0
NET EARNINGS ATTRIBUTABLE TO ENSTAR GROUP LIMITED										$ 1,714	$ (74,000)