SEGMENT INFORMATION (DETAILS 2) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Revenues From External Customers By Geographic Location Of Subsidiary [Line Items]
Gross premiums written	$ 4,970,208	$ 4,603,730	$ 4,711,519
Bermuda [Member]
Revenues From External Customers By Geographic Location Of Subsidiary [Line Items]
Gross premiums written	465,980	525,226	618,273
Ireland [Member]
Revenues From External Customers By Geographic Location Of Subsidiary [Line Items]
Gross premiums written	1,650,229	1,532,753	1,641,767
U.S. [Member]
Revenues From External Customers By Geographic Location Of Subsidiary [Line Items]
Gross premiums written	2,562,789	2,364,099	2,309,107
Other [Member]
Revenues From External Customers By Geographic Location Of Subsidiary [Line Items]
Gross premiums written	$ 291,210	$ 181,652	$ 142,372