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Significant Accounting Policies (Narrative) (Details) shares in Millions |  | 1 Months Ended | 3 Months Ended | 12 Months Ended |
--- | --- | --- | --- | --- | ---
Jan. 08, 2016 USD ($) | Jan. 31, 2010 right | Mar. 31, 2016 USD ($) shares | Mar. 31, 2015 USD ($) shares | Dec. 31, 2015 USD ($) | Aug. 31, 2014 USD ($)
Earnings (Loss) Per Share |  |  |  |  |  |
Common shares excluded from computation | shares |  |  | 3.5 | 4.5 |  |
Cash, Cash Equivalents and Short-term Investments |  |  |  |  |  |
Maturity period of cash and cash equivalents, maximum |  |  | 3 months |  |  |
Maturity period of short term investments, minimum |  |  | 3 months |  |  |
Inventory, Net [Abstract] |  |  |  |  |  |
Inventory write downs |  |  | $ 0 | $ 0 |  |
Goodwill and Other Identifiable Intangible Assets |  |  |  |  |  |
Finite-lived intangible asset, useful life |  |  | 20 years |  |  |
Amortization expense |  |  | $ 2,500,000 | 600,000 |  |
Impairment of goodwill |  |  | 0 | 0 |  |
Amortization Expense |  |  |  |  |  |
Amortization expense 2016 |  |  | 10,600,000 |  |  |
Amortization expense 2017 |  |  | 10,700,000 |  |  |
Amortization expense 2018 |  |  | 10,700,000 |  |  |
Amortization expense 2019 |  |  | 10,700,000 |  |  |
Amortization expense 2020 |  |  | 10,700,000 |  |  |
Property and Equipment |  |  |  |  |  |
Depreciation |  |  | 100,000 | 100,000 |  |
Contingent Liabilities |  |  |  |  |  |
Purchase of commercial license rights |  |  | $ 92,855,000 | 0 |  |
Revenue Recognition |  |  |  |  |  |
Restocking fee (percent) |  |  | 20.00% |  |  |
Minimum |  |  |  |  |  |
Revenue Recognition |  |  |  |  |  |
Period when partner sales reports are received after end of quarter |  |  | 30 days |  |  |
Maximum |  |  |  |  |  |
Revenue Recognition |  |  |  |  |  |
Period when partner sales reports are received after end of quarter |  |  | 60 days |  |  |
Equipment | Minimum |  |  |  |  |  |
Property and Equipment |  |  |  |  |  |
Estimated useful life of assets |  |  | 3 years |  |  |
Equipment | Maximum |  |  |  |  |  |
Property and Equipment |  |  |  |  |  |
Estimated useful life of assets |  |  | 10 years |  |  |
OMT, Inc. |  |  |  |  |  |
Property, Plant and Equipment [Line Items] |  |  |  |  |  |
Goodwill acquired | $ 60,800,000 |  |  |  |  |
Finite-lived intangible assets | $ 167,000,000 |  |  |  |  |
Cydex Pharmaceuticals, Inc |  |  |  |  |  |
Contingent Liabilities |  |  |  |  |  |
Fair value of liability |  |  | $ 6,900,000 |  | $ 9,500,000 |
Contingent liability change in amount |  |  | 200,000 | 1,200,000 |  |
Cydex Pharmaceuticals, Inc | Revenue Sharing |  |  |  |  |  |
Contingent Liabilities |  |  |  |  |  |
Purchase of commercial license rights |  |  | 2,800,000 | 3,200,000 |  |
Metabasis Therapeutics |  |  |  |  |  |
Contingent Liabilities |  |  |  |  |  |
Fair value of liability |  |  | 2,400,000 |  | 4,000,000 |
Contingent liability change in amount |  |  | (1,100,000) | 1,200,000 |  |
Number of contingent value rights | right |  | 4 |  |  |  |
Number of contingent value rights per series of contingent value rights | right |  | 1 |  |  |  |
Number of contingent value rights issued for each share | right |  | 4 |  |  |  |
Contingent value rights, frequency of cash payment |  | 6 months |  |  |  |
Contingent liability, cash payment |  |  | 2,600,000 | 0 |  |
Omthera Pharmaceuticals |  |  |  |  |  |
Milestone Payments |  |  |  |  |  |
Milestone payment received |  |  |  |  | 0 |
2019 convertible senior notes |  |  |  |  |  |
Convertible Debt |  |  |  |  |  |
Principal amount outstanding |  |  | 245,000,000 |  | $ 245,000,000 |
2019 convertible senior notes | Senior Notes |  |  |  |  |  |
Convertible Debt |  |  |  |  |  |
Principal amount outstanding |  |  |  |  |  | $ 245,000,000.0
Interest rate |  |  |  |  |  | 0.75%
Acquired in-process research and development |  |  |  |  |  |
Goodwill and Other Identifiable Intangible Assets |  |  |  |  |  |
Impairment of IPR&D |  |  | $ 0 | $ 0 |  |

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