Business and Significant Accounting Policies (Details 5) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Business and Significant Accounting Policies
Net loss	$ (174,456)	$ (139,881)	$ (46,140)
Net loss per share-basic and diluted (in dollars per share)	$ (1.72)	$ (1.42)	$ (0.55)
Shares used in the computation of net loss per share-basic and diluted	101,174,000	98,289,000	84,392,000
Continuing operations
Anti-dilutive Securities
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	7,027,000	4,172,000	5,357,000