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		307	573,460
Buybacks of ordinary shares		(267)	(566,673)
Exercise of stock options		1	1,195
Share based compensation expense			29,261
Change in net unrealized gains (losses) on investments, net of tax				291,330
Change in net unrealized gains (losses) on affiliate and other investments, net of tax	35,620			35,620
Change in OTTI losses recognized in other comprehensive income, net of tax				28,119
Change in underfunded pension liability	1,287			1,287
Change in value of cash flow hedge	330			330
Foreign currency translation adjustments	(1,278)			(1,278)
Net income (loss) attributable to XL Group plc	40,777				40,777
Dividends on ordinary shares					(104,020)
Non-controlling interests - contribution						0
Non-controlling interests						4
Non-controlling interest share in change in accumulated other comprehensive income (loss)						(16)
Purchase of Series E preference ordinary shares						(500)
Balance at Sep. 30, 2011	10,928,706	3,206	9,030,259	456,203	437,254	1,001,784
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	1,380
Buybacks of ordinary shares		(162)	(350,996)
Exercise of stock options		3	4,784
Share based compensation expense			36,530
Change in net unrealized gains (losses) on investments, net of tax				778,299
Change in net unrealized gains (losses) on affiliate and other investments, net of tax	30,998			30,998
Change in OTTI losses recognized in other comprehensive income, net of tax				52,353
Change in underfunded pension liability	(2,033)			(2,033)
Change in value of cash flow hedge	330			330
Foreign currency translation adjustments	(19,563)			(19,563)
Net income (loss) attributable to XL Group plc	569,686				569,686
Dividends on ordinary shares					(102,239)
Non-controlling interests - contribution						1,500
Non-controlling interests						(63)
Non-controlling interest share in change in accumulated other comprehensive income (loss)						473
Purchase of Series E preference ordinary shares						0
Balance at Sep. 30, 2012	$ 11,757,419	$ 3,006	$ 8,630,377	$ 1,423,448	$ 354,206	$ 1,346,382