Fair Value Measurements (Details) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Fair value of assets and liabilities measured on a recurring basis
Transfers or reclassifications of securities from Level 1 to Level 2	$ 0
Transfers or reclassifications of securities from Level 2 to Level 1	0
Estimate of Fair Value Measurement
Fair value of assets and liabilities measured on a recurring basis
Total Assets	310,368	$ 102,144
Total Liabilities	220,192	218,702
Estimate of Fair Value Measurement \| MuGard
Fair value of assets and liabilities measured on a recurring basis
Total Liabilities	8,561	12,102
Estimate of Fair Value Measurement \| Acquisition Related Contingent Consideration \| Lumara Health
Fair value of assets and liabilities measured on a recurring basis
Total Liabilities	211,631	206,600
Estimate of Fair Value Measurement \| Money market funds
Fair value of assets and liabilities measured on a recurring basis
Total Assets	1,844	77,254
Estimate of Fair Value Measurement \| Corporate debt securities
Fair value of assets and liabilities measured on a recurring basis
Total Assets	155,595	24,890
Estimate of Fair Value Measurement \| Commercial paper.
Fair value of assets and liabilities measured on a recurring basis
Total Assets	48,223
Estimate of Fair Value Measurement \| Certificates of deposit
Fair value of assets and liabilities measured on a recurring basis
Total Assets	20,001
Estimate of Fair Value Measurement \| Municipal securities
Fair value of assets and liabilities measured on a recurring basis
Total Assets	84,705
Fair Value, Inputs, Level 1
Fair value of assets and liabilities measured on a recurring basis
Total Assets	1,844	77,254
Fair Value, Inputs, Level 1 \| Money market funds
Fair value of assets and liabilities measured on a recurring basis
Total Assets	1,844	77,254
Fair Value, Inputs, Level 2
Fair value of assets and liabilities measured on a recurring basis
Total Assets	308,524	24,890
Fair Value, Inputs, Level 2 \| Corporate debt securities
Fair value of assets and liabilities measured on a recurring basis
Total Assets	155,595	24,890
Fair Value, Inputs, Level 2 \| Commercial paper.
Fair value of assets and liabilities measured on a recurring basis
Total Assets	48,223
Fair Value, Inputs, Level 2 \| Certificates of deposit
Fair value of assets and liabilities measured on a recurring basis
Total Assets	20,001
Fair Value, Inputs, Level 2 \| Municipal securities
Fair value of assets and liabilities measured on a recurring basis
Total Assets	84,705
Fair Value, Inputs, Level 3
Fair value of assets and liabilities measured on a recurring basis
Total Liabilities	220,192	218,702
Fair Value, Inputs, Level 3 \| MuGard
Fair value of assets and liabilities measured on a recurring basis
Total Liabilities	8,561	12,102
Fair Value, Inputs, Level 3 \| Acquisition Related Contingent Consideration \| Lumara Health
Fair value of assets and liabilities measured on a recurring basis
Total Liabilities	$ 211,631	$ 206,600

Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258

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+ References

No definition available.

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Amount of transfers of assets measured on a recurring basis out of Level 1 of the fair value hierarchy into Level 2.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (bb)

-URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258

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Amount of transfers of assets measured on a recurring basis out of Level 2 of the fair value hierarchy into Level 1.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (bb)

-URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258

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Fair value of financial and nonfinancial obligations.

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