Veloce - Additional Information (Details) (USD $) Share data in Millions, unless otherwise specified	3 Months Ended			12 Months Ended					46 Months Ended
	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2012	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2011	Mar. 31, 2013 Veloce Technologies, Inc. [Member]	Mar. 31, 2012 Veloce Technologies, Inc. [Member]	Mar. 31, 2013 Veloce Technologies, Inc. [Member]	Dec. 31, 2012 Veloce Technologies, Inc. [Member]	Jun. 20, 2012 Veloce Technologies, Inc. [Member]
Veloce (Textual) [Abstract]
Initial consideration according to merger agreement											$ 60,400,000
Aggregate shares issued							3.0
Shares issued for Veloce merger consideration				16,565,000	0	0	16,565,000
Payment of aggregate consideration as cash				0	0	31,484,000	16,600,000
Total consideration to be transferred										178,500,000	135,000,000
Research and development expense recognized upon the probable achievement of the first performance milestone	9,600,000	51,900,000	60,400,000	187,419,000	175,656,000	108,732,000		60,400,000
Immaterial R&D expense error								8,000,000
Total research and development expenses expected to be incurred							142,800,000		142,800,000
Research and development expenses incurred							$ 66,200,000		$ 126,600,000