DIVIDENDS (Detail) - The Company paid dividends to Series C and Series E preference shareholders, and declared dividends (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2009
Preference ordinary shares	$ 0		$ 34,694		$ 80,200
Series C Preferred Stock [Member]
Preference ordinary shares	5,300		7,900		23,200
Series D Preferred Stock [Member]
Preference ordinary shares	0	[1]	0	[1]	0	[1]
Series E Preferred Stock [Member]
Preference ordinary shares	$ 66,200		$ 69,900		$ 65,000

[1] On December 16, 2011, the Company announced that the Board of Directors of XL-Cayman resolved to pay a dividend of $9.1084 per share on XL-Cayman's Series D Preference Ordinary Shares. The dividend was paid on January 17, 2012 to all shareholders of record as of January 3, 2012.