Interim Consolidated Statements of Shareholders' Equity and Comprehensive Income (Unaudited) (Parenthetical) (USD $) In Thousands	3 Months Ended		9 Months Ended			12 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011		Sep. 30, 2010	Dec. 31, 2010
Total comprehensive income	$ 28,538	$ 107,609	$ 191,607	[1]	$ 167,260	$ 256,558

[1] Total comprehensive income for the three months ended September 30, 2011 and 2010 was $28,538 and $107,609, respectively and $167,260 for the nine months ended September 30, 2010.