XML 24 R104.htm IDEA: XBRL DOCUMENT

Employee Benefit Plans (Details 4) (USD $)	12 Months Ended
Employee Benefit Plans (Details 4) (USD $)	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Defined contribution plan
Defined contribution expenses	$ 8,100,000	$ 10,900,000	$ 7,800,000
Defined Contribution Plan
Defined contribution plan
Defined contribution expenses	9,900,000	11,400,000	6,200,000
Defined Contribution Plan \| U.S.
Defined contribution plan
Maximum amount that can be contributed by eligible participants	16,500
Percentage by which employer contribution matches up to 6% of participant's compensation	100.00%
Maximum percentage of participant's compensation eligible for employer contribution match	6.00%
Core contribution made by the company as a percentage of participant's compensation	6.00%
Requisite service period under defined contribution plan (in years)	1 year
Defined Contribution Plan \| Bermuda
Defined contribution plan
Maximum amount that can be contributed by eligible participants	$ 16,500
Percentage by which employer contribution matches up to 6% of participant's compensation	100.00%
Maximum percentage of participant's compensation eligible for employer contribution match	6.00%
Core contribution made by the company as a percentage of participant's compensation	6.00%
Requisite service period under defined contribution plan (in years)	1 year

The compensation expense recognized during the period pertaining to the deferred compensation arrangement.

The minimum period that the individual is required to perform services in order to be fully vested under the deferred compensation arrangement.