Fair Value Measurements - Assets And Liabilities Measured At Fair Value (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Assets:
Equity securities	$ 22,183
Fair Value, Measurements, Recurring
Assets:
Equity securities	22,183	$ 12,461
Common stock options/warrants	1,511	3,333
Total assets	23,717	15,901
Liabilities:
Total liabilities	28,948	41,670
Fair Value, Measurements, Recurring | Quoted prices in active markets for identical assets (Level 1)
Assets:
Equity securities	22,183	12,461
Common stock options/warrants	0	0
Total assets	22,183	12,568
Liabilities:
Total liabilities	0	0
Fair Value, Measurements, Recurring | Significant other observable inputs (Level 2)
Assets:
Equity securities	0	0
Common stock options/warrants	1,511	3,333
Total assets	1,534	3,333
Liabilities:
Total liabilities	0	317
Fair Value, Measurements, Recurring | Significant unobservable inputs (Level 3)
Assets:
Equity securities	0	0
Common stock options/warrants	0	0
Total assets	0	0
Liabilities:
Total liabilities	28,948	41,353
Fair Value, Measurements, Recurring | Forward contracts
Liabilities:
Total liabilities		317
Fair Value, Measurements, Recurring | Forward contracts | Quoted prices in active markets for identical assets (Level 1)
Liabilities:
Total liabilities		0
Fair Value, Measurements, Recurring | Forward contracts | Significant other observable inputs (Level 2)
Liabilities:
Total liabilities		317
Fair Value, Measurements, Recurring | Forward contracts | Significant unobservable inputs (Level 3)
Liabilities:
Total liabilities		0
Fair Value, Measurements, Recurring | Contingent consideration
Liabilities:
Total liabilities	28,948	41,353
Fair Value, Measurements, Recurring | Contingent consideration | Quoted prices in active markets for identical assets (Level 1)
Liabilities:
Total liabilities	0	0
Fair Value, Measurements, Recurring | Contingent consideration | Significant other observable inputs (Level 2)
Liabilities:
Total liabilities	0	0
Fair Value, Measurements, Recurring | Contingent consideration | Significant unobservable inputs (Level 3)
Liabilities:
Total liabilities	28,948	41,353
Money market funds | Fair Value, Measurements, Recurring
Assets:
Money market funds		107
Money market funds | Fair Value, Measurements, Recurring | Quoted prices in active markets for identical assets (Level 1)
Assets:
Money market funds		107
Money market funds | Fair Value, Measurements, Recurring | Significant other observable inputs (Level 2)
Assets:
Money market funds		0
Money market funds | Fair Value, Measurements, Recurring | Significant unobservable inputs (Level 3)
Assets:
Money market funds		$ 0
Forward contracts | Fair Value, Measurements, Recurring
Assets:
Derivative Asset	23
Forward contracts | Fair Value, Measurements, Recurring | Quoted prices in active markets for identical assets (Level 1)
Assets:
Derivative Asset	0
Forward contracts | Fair Value, Measurements, Recurring | Significant other observable inputs (Level 2)
Assets:
Derivative Asset	23
Forward contracts | Fair Value, Measurements, Recurring | Significant unobservable inputs (Level 3)
Assets:
Derivative Asset	$ 0