Capital Stock (Details) (USD $) In Thousands, except Share data	9 Months Ended		3 Months Ended	9 Months Ended
	Sep. 30, 2011	Dec. 31, 2010	Sep. 30, 2011 CEO Program [Member]	Sep. 30, 2011 CEO Program [Member]
Capital Stock [Line Items]
Issuance of common stock	$ 853,441		$ 1,295,000	$ 2,090,000
Common stock available for sale	100,000,000	100,000,000	5,000,000	5,000,000
Sales commissions and fees			35,704	59,038
Amount charged to additional paid in capital in connection with the issuance			$ 487	$ 857