Consolidated Statements of Cash Flow (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2018
Shares used to satisfy exercise costs and recipients' income tax obligations	75,214	8,875
Forfeiture of certain shares to satisfy exercise costs and the recipients income tax obligations related to stock options exercised and restricted stock vested	$ 2,589	$ 467
Upfront cash consideration and contingent consideration included in other current liabilities	$ 2,443	$ 77,600
Shares not settled		200,000
Value of unsettled shares		$ 8,800
PML JV
Percentage of membership interest in joint venture by other party	10.00%	10.00%