Share Capital (Details) (USD $) In Thousands, except Share data, unless otherwise specified			6 Months Ended
	Jun. 30, 2012	Dec. 31, 2011	Jun. 30, 2012 Common Stock [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at December 31, 2011 (shares)	258,861,960	258,669,487	258,669,487
Balance at December 31, 2011	$ 694,341	$ 693,899	$ 693,899
Option exercises (shares)			78,333
Option exercises			134
Unclaimed shares forfeited (shares)			(50,869)
Unclaimed shares forfeited			0
Bonus shares and other (shares)			165,009
Bonus shares and other			308
Balance at June 30, 2012 (shares)	258,861,960	258,669,487	258,861,960
Balance at June 30, 2012	$ 694,341	$ 693,899	$ 694,341