Fair Value Measurements - Assets And Liabilities Measured At Fair Value (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Assets:
Equity securities	$ 12,879
Fair Value, Measurements, Recurring
Assets:
Equity securities	12,879	$ 12,461
Common stock options/warrants	5,004	3,333
Total assets	17,883	15,901
Liabilities:
Total liabilities	43,216	41,670
Fair Value, Measurements, Recurring | Quoted prices in active markets for identical assets (Level 1)
Assets:
Equity securities	12,879	12,461
Common stock options/warrants	0	0
Total assets	12,879	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	5,004	3,333
Total assets	5,004	3,333
Liabilities:
Total liabilities	104	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	43,112	41,353
Fair Value, Measurements, Recurring | Forward contracts
Liabilities:
Total liabilities	104	317
Fair Value, Measurements, Recurring | Forward contracts | Quoted prices in active markets for identical assets (Level 1)
Liabilities:
Total liabilities	0	0
Fair Value, Measurements, Recurring | Forward contracts | Significant other observable inputs (Level 2)
Liabilities:
Total liabilities	104	317
Fair Value, Measurements, Recurring | Forward contracts | Significant unobservable inputs (Level 3)
Liabilities:
Total liabilities	0	0
Fair Value, Measurements, Recurring | Contingent consideration
Liabilities:
Total liabilities	43,112	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	$ 43,112	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