Net Income (Loss) Per Share Attributable To Common Stockholders (Reconciliation Of Basic To Diluted Weighted Average Common Shares Outstanding) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2009		Dec. 31, 2008
Weighted Average Number of Shares Outstanding Reconciliation [Line Items]
Basic	116,904,000		115,062,000		114,176,000
Dilutive common stock options	190,000	[1]	212,000	[1]		[1]
Contingently issuable - performance shares	424,000	[1]	646,000	[1]		[1]
Convertible notes dilution	1,697,000	[2]	410,000	[2]		[2]
Diluted	119,215,000		116,330,000		114,176,000
Convertible Senior Notes issued	$ 2,601,915		$ 2,700,185
Senior Notes, interest rate, percentage							2.875%
2.875% Convertible Senior Notes [Member]
Weighted Average Number of Shares Outstanding Reconciliation [Line Items]
Convertible Senior Notes issued	$ 479,900						500,000
Senior Notes, interest rate, percentage	2.875%
Stock Options [Member]
Weighted Average Number of Shares Outstanding Reconciliation [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	173,915
Performance Shares [Member]
Weighted Average Number of Shares Outstanding Reconciliation [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	223,969

[1] Diluted earnings per share were calculated using the two-class method for the years ended December 31, 2011, 2010 and 2009. The following common stock equivalents were excluded from the diluted loss per share calculations for the year ended 2009 because they would have been anti-dilutive to the calculations: 173,915 outstanding options to purchase the Company's common stock and 223,969 performance shares.

[2] During January 2008, the Company issued $500 million of 2.875% Convertible Senior Notes. Weighted average common shares outstanding have been increased to reflect the dilutive effect that would have resulted if the 2.875% Convertible Senior Notes had qualified for and been converted during the years ended December 31, 2011 and 2010, respectively. The 2.875% Convertible Senior Notes were not dilutive to the per share calculations of 2009.