Consolidated Financial Statements (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended	6 Months Ended
Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Income (numerator)
Net (loss) income	$ (12,589)	$ 7,019	$ (10,770)	$ 87
Shares (denominator)
Weighted-average basic common shares outstanding (in shares)	92,767	92,069	92,625	91,978
Effect of dilutive securities-stock rights (in shares)	0	496	0	540
Weighted-average diluted common shares outstanding (in shares)	92,767	92,565	92,625	92,518
Basic and diluted net (loss) income per share:
Basic net (loss) income per share (in dollars per share)	$ (0.14)	$ 0.08	$ (0.12)	$ 0.00
Diluted net (loss) income per share (in dollars per share)	$ (0.14)	$ 0.08	$ (0.12)	$ 0.00
Anti-dilutive weighted-average stock rights outstanding (in shares)	5,913	7,967	4,308	7,690

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