Stockholders' Equity (Details) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Class of Stock [Line Items]
Company authorized the repurchase of common stock	$ 300,000
Common stock shares repurchased (in shares)	8,620,689	21,721,959
Warrants issued	8,823,529
Warrant exercise price decrease (in hundredths)		9.48%
Shares reserved (in shares)	62,599,297
Class B Convertible Common Stock [Member]
Class of Stock [Line Items]
Voting rights per share	10
Common Stock [Member]
Class of Stock [Line Items]
Voting rights per share	1
Common stock options outstanding [Member]
Class of Stock [Line Items]
Shares reserved (in shares)	384,000
Restricted stock units outstanding [Member]
Class of Stock [Line Items]
Shares reserved (in shares)	891,000
Available to grant 2007 Stock Incentive Program - [Member]
Class of Stock [Line Items]
Shares reserved (in shares)	1,534,000
Phantom stock units outstanding [Member]
Class of Stock [Line Items]
Shares reserved (in shares)	87,000
Phantom stock units available to grant [Member]
Class of Stock [Line Items]
Shares reserved (in shares)	95,000
Common stock warrants [Member]
Class of Stock [Line Items]
Shares reserved (in shares)	8,823,529
Common stock warrants [Member] | Exercise Price $18.10 [Member]
Class of Stock [Line Items]
Warrants issued	7,000,000
Exercise price (in dollars per share)	$ 18.10
Common stock warrants [Member] | Exercise Price $27.43 [Member]
Class of Stock [Line Items]
Warrants issued	1,823,529
Exercise price (in dollars per share)	$ 27.43
Exchangeable Unsecured Notes, Due 2102 [Member]
Class of Stock [Line Items]
Shares reserved (in shares)	6,176,471
Convertible Senior Debentures, Due 2040 [Member]
Class of Stock [Line Items]
Aggregate cost of common stock repurchased		275,000
Shares reserved (in shares)	22,285,258
Number of shares debentures are convertible into (in shares)	19,809,103
Convertible Senior Debentures, Due 2041 [Member]
Class of Stock [Line Items]
Shares reserved (in shares)	8,870,490
Number of shares debentures are convertible into (in shares)	7,884,885
Conversion of Class B common stock [Member]
Class of Stock [Line Items]
Shares reserved (in shares)	13,452,549