UNAUDITED CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY (USD $) In Thousands	Total	Ordinary Shares	Additional Paid in Capital	Accumulated Other Comprehensive Income (Loss)	Retained Earnings (Deficit)	Non-controlling Interest in Equity of Consolidated Subsidiaries
Balance at Dec. 31, 2010		$ 3,165	$ 8,993,016	$ 100,795	$ 500,497	$ 1,002,296
Issuance of ordinary shares		3	976
Buybacks of ordinary shares		(116)	(258,787)
Exercise of stock options		0	1,087
Share based compensation expense			20,008
Change in net unrealized gains (losses) on investments, net of tax				181,206
Change in net unrealized gains (losses) on affiliate and other investments, net of tax	32,666			32,666
Change in OTTI losses recognized in other comprehensive income, net of tax				24,124
Change in underfunded pension liability	(397)			(397)
Change in value of cash flow hedge	220			220
Foreign currency translation adjustments	84,357			84,357
Net income (loss) attributable to XL Group plc	(1,621)				(1,621)
Dividends on ordinary shares					(68,529)
Non-controlling interests - contribution						0
Non-controlling interests						1
Non-controlling interest share in change in AOCI						(16)
Purchase of preference ordinary shares						(500)
Balance at Jun. 30, 2011	10,614,451	3,052	8,756,300	422,971	430,347	1,001,781
Balance at Dec. 31, 2011	10,756,130	3,156	8,938,679	583,064	(113,241)	1,344,472
Issuance of ordinary shares		9	1,376
Buybacks of ordinary shares		(109)	(225,869)
Exercise of stock options		1	1,349
Share based compensation expense			22,669
Change in net unrealized gains (losses) on investments, net of tax				321,657
Change in net unrealized gains (losses) on affiliate and other investments, net of tax	16,383			16,383
Change in OTTI losses recognized in other comprehensive income, net of tax				26,417
Change in underfunded pension liability	(7)			(7)
Change in value of cash flow hedge	220			220
Foreign currency translation adjustments	(36,974)			(36,974)
Net income (loss) attributable to XL Group plc	397,784				397,784
Dividends on ordinary shares					(68,755)
Non-controlling interests - contribution						1,500
Non-controlling interests						(12)
Non-controlling interest share in change in AOCI						33
Purchase of preference ordinary shares						0
Balance at Jun. 30, 2012	$ 11,213,802	$ 3,057	$ 8,738,204	$ 910,760	$ 215,788	$ 1,345,993