Income Taxes - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2017
Tax Carryforwards
Unrealized gain	$ 7,967,000	$ 1,088,000
Federal statutory income tax rate (percent)	35.00%	35.00%	35.00%
Deferred tax liabilities recognized in other liabilities, excluding current portion	$ 134,063,000	$ 110,439,000
Unrecognized tax benefits	0	425,000	$ 880,000
Income tax penalties and interest accrued	0
Increase in valuation allowance	(14,800,000)
Deferred tax liabilities not recognized, undistributed foreign earnings	0
BioAxone Biosciences, Inc
Tax Carryforwards
Deferred tax liabilities recognized in other liabilities, excluding current portion	134,000,000	$ 110,400,000
State and Local Jurisdiction
Tax Carryforwards
Operating loss carryforwards	975,800,000
Tax credit carryforwards	103,800,000
Internal Revenue Service (IRS)
Tax Carryforwards
Operating loss carryforwards	4,100,000,000
Tax credit carryforwards	$ 262,900,000
Accounting Standards Update 2016-09 | Scenario, Forecast | Retained Earnings | State and Local Jurisdiction
Tax Carryforwards
Operating loss carryforwards				$ 190,000,000
Accounting Standards Update 2016-09 | Scenario, Forecast | Retained Earnings | Domestic Tax Authority
Tax Carryforwards
Operating loss carryforwards				$ 1,200,000,000