Other Arrangements (Details) - USD ($) |
12 Months Ended | |
---|---|---|
Dec. 31, 2008 |
Jun. 30, 2017 |
|
Other Income and Expenses [Abstract] | ||
Gross proceeds from sale of royalty rights receivable from GlaxoSmithKline | $ 160,000,000.0 | |
Deferred revenue royalty purchase agreement | $ 9,600,000 |