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		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Basic earnings per ordinary share & ordinary share equivalents outstanding:
Net income (loss) attributable to ordinary shareholders	$ 135,648	$ 171,902	$ 759,136	$ 569,684
Weighted average ordinary shares outstanding - basic	285,393	304,199	289,957	309,675
Basic earnings per ordinary share & ordinary share equivalents outstanding	$ 0.48	$ 0.57	$ 2.62	$ 1.84
Diluted earnings per ordinary share & ordinary share equivalents outstanding:
Impact of share-based compensation and certain conversion features	5,097	3,565	4,871	2,927
Weighted average ordinary shares outstanding - diluted	290,490	307,764	294,828	312,602
Diluted earnings per ordinary share & ordinary share equivalents outstanding	$ 0.47	$ 0.56	$ 2.57	$ 1.82
Dividends per ordinary share	$ 0.14	$ 0.11	$ 0.42	$ 0.33