Stock-Based Compensation (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Share-based Payment Arrangement, Noncash Expense [Abstract]
Stock options and other incentive awards granted (in shares)	35,240	27,590	190,320	211,326
Stock-Based Compensation
Allocated share-based compensation expense	$ 2,295	$ 2,639	$ 7,083	$ 7,707
Unrecognized stock-based compensation cost, net of estimated forfeiture	10,100		10,100
Research and development
Stock-Based Compensation
Allocated share-based compensation expense	110	162	352	503
Selling, general and administrative expenses
Stock-Based Compensation
Allocated share-based compensation expense	$ 2,185	$ 2,477	$ 6,731	$ 7,204

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

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