Fair Value Measurements (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		12 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration liability	$ 16,200	$ 15,900	$ 15,700
Auction rate securities	2,208		2,208
Maturity period of US government subsidized securities (in years)	10 years
Duration of securities subject to temporary impairment, minimum (in months)	12 months
Amount of temporary impairment	192		192
Auction Rate Securities [Member]
Summary of activities in financial instruments with significant Level 3 inputs [Roll Forward]
Balance at beginning of period	2,208	3,240	3,240
Transfers into Level 3	0	0
Total gains (losses)
Included in net loss	0	0
Included in other comprehensive loss	0	8
Settlements at par	0	(100)
Balance at end of period	2,208	3,148	2,208
Changes in unrealized gains or losses for the period included in earnings (or changes in net assets) for assets or liabilities held at the end of the reporting period	0	0
Fair Value Measurements, Quantitative Information
Fair Value	2,208		2,208
Valuation technique	Discounted cash flow model		Discounted cash flow model
Auction Rate Securities [Member] | Minimum [Member]
Fair Value Measurements, Quantitative Information
Redemption period	5 years		5 years
Discount Rate	0.25%		0.25%
Auction Rate Securities [Member] | Maximum [Member]
Fair Value Measurements, Quantitative Information
Redemption period	15 years		15 years
Discount Rate	3.00%		3.00%
Auction Rate Securities [Member] | Weighted average [Member]
Fair Value Measurements, Quantitative Information
Redemption period	6 years		6 years
Discount Rate	1.55%		1.55%
Azedra commercialization [Member]
Fair Value Measurements, Quantitative Information
Period of milestone expected achievement	2017		2017
Fair Value	2,300		2,300
Valuation technique	Probability adjusted discounted cash flow model		Probability adjusted discounted cash flow model
Discount Rate	10.00%		10.00%
Probability of success	40.00%		40.00%
MIP - 1404 commercialization [Member]
Fair Value Measurements, Quantitative Information
Period of milestone expected achievement	2018		2018
Fair Value	2,100		2,000
Valuation technique	Probability adjusted discounted cash flow model		Probability adjusted discounted cash flow model
Discount Rate	10.00%		10.00%
Probability of success	31.00%		31.00%
MIP-1095 commercialization [Member]
Fair Value Measurements, Quantitative Information
Period of milestone expected achievement	2021		2021
Fair Value	500		500
Valuation technique	Probability adjusted discounted cash flow model		Probability adjusted discounted cash flow model
Discount Rate	10.00%		10.00%
Probability of success	19.00%		19.00%
Net sales targets [Member]
Fair Value Measurements, Quantitative Information
Fair Value	11,300		10,900
Valuation technique	Monte-Carlo simulation		Monte-Carlo simulation
Discount Rate	12.50%		12.50%
Net sales targets [Member] | Minimum [Member]
Fair Value Measurements, Quantitative Information
Period of milestone expected achievement	2018		2018
Probability of success	19.00%		19.00%
Net sales targets [Member] | Maximum [Member]
Fair Value Measurements, Quantitative Information
Period of milestone expected achievement	2022		2022
Probability of success	40.00%		40.00%
Net sales targets [Member] | Weighted average [Member]
Fair Value Measurements, Quantitative Information
Probability of success	32.80%		32.80%
Contingent Consideration Liability [Member]
Summary of activities in financial instruments with significant Level 3 inputs [Roll Forward]
Balance at beginning of period	15,700	0	0
Total gains (losses)
Fair value of contingent consideration - acquisition of Molecular Insight	0	15,900
Fair value change to contingent consideration included in net loss	500	0
Balance at end of period	16,200	15,900
Changes in unrealized gains or losses for the period included in earnings (or changes in net assets) for assets or liabilities held at the end of the reporting period	500	0
U.S. Government Subsidized Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Auction rate securities	2,208
Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration liability	16,200		15,700
Money Market Funds	85,373		60,364
Auction rate securities	2,208		2,208
Asset, total	87,581		62,572
Liability, total	16,200		15,700
Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration liability	0		0
Money Market Funds	85,373		60,364
Auction rate securities	0		0
Asset, total	85,373		60,364
Liability, total	0		0
Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration liability	0		0
Money Market Funds	0		0
Auction rate securities	0		0
Asset, total	0		0
Liability, total	0		0
Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration liability	16,200		15,700
Money Market Funds	0		0
Auction rate securities	2,208		2,208
Asset, total	2,208		2,208
Liability, total	$ 16,200		$ 15,700