Computation of Earnings Per Ordinary Share and Ordinary Share Equivalent - Computation of Basic and Diluted Earnings Per Share (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Basic earnings per ordinary share & ordinary share equivalents outstanding:
Net income (loss) attributable to ordinary shareholders	$ 272,698	$ 221,154	$ 623,487	$ 397,782
Weighted average ordinary shares outstanding - basic	289,513	309,765	292,277	312,442
Basic earnings per ordinary share & ordinary share equivalents outstanding	$ 0.94	$ 0.71	$ 2.13	$ 1.27
Diluted earnings per ordinary share & ordinary share equivalents outstanding:
Impact of share-based compensation and certain conversion features	4,820	2,670	4,767	2,568
Weighted average ordinary shares outstanding - diluted	294,333	312,435	297,044	315,010
Diluted earnings per ordinary share & ordinary share equivalents outstanding	$ 0.93	$ 0.71	$ 2.10	$ 1.26
Dividends per ordinary share	$ 0.14	$ 0.11	$ 0.28	$ 0.22