Share-Based Payments - SOP 2015 (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Aug. 25, 2016	Sep. 23, 2015	Apr. 02, 2015
Additional disclosures
Share-based compensation expense	$ 9,748	$ 5,154	$ 5,732
SOP 2015
Options
Outstanding at beginning of year (in shares)	2,842,913	3,044,899	1,794,360
Granted (in shares)			1,458,300
Forfeited (in shares)	(552,319)	(201,986)	(207,761)
Outstanding at end of year (in shares)	2,290,594	2,842,913	3,044,899
Vested and exercisable at end of year (in shares)	1,984,911	1,844,590	989,656
Weighted average exercise price in $ per share
Outstanding balance at beginning of year (in dollars per share)	$ 8.34	$ 8.35	$ 7.83
Granted (in dollars per share)			9.02
Forfeited (in dollars per share)	8.40	8.41	8.60
Outstanding balance at end of year (in dollars per share)	8.33	8.34	8.35
Vested and exercisable balance at end of year (in dollars per share)	8.20	$ 8.10	$ 7.68
SOP 2015 | $4.06 per share to $11.00 per share
Additional disclosures
Exercise price minimum range	4.06
Exercise price maximum range	$ 11.00
Weighted average remaining contractual life	6 years 4 months 24 days
SOP 2015 | Stock Options
Share-Based Payments
Vesting period	4 years
Options
Granted (in shares)	0	0
Additional disclosures
Share-based compensation expense	$ 4,000	$ 3,200	$ 5,600
Weighted-average grant date fair value (in dollars per share)		$ 5.05
Fair Value Assumptions
Expected term of options (in years)			6 years 1 month 6 days
Dividend yield (as a percent)			0.00%
Total unrecognized compensation related to unvested options	$ 1,600
Recognition period	1 year 3 months 18 days
SOP 2015 | Stock Options | Minimum
Fair Value Assumptions
Expected volatility (as a percent)			55.60%
Risk-free interest rate (as a percent)			1.90%
SOP 2015 | Stock Options | Maximum
Share-Based Payments
Exercise period	10 years
Fair Value Assumptions
Expected volatility (as a percent)	62.00%
Risk-free interest rate (as a percent)			2.10%
SOP 2015 | Stock Options | Vesting period, year one
Share-Based Payments
Percentage that vests during the period	25.00%
SOP 2015 | Stock Options | Vesting period, years 2-4
Share-Based Payments
Percentage that vests during the period	75.00%
Monthly vesting percentage	2.083%
Nabriva Therapeutics AG (“Nabriva Austria”) | Common Stock | SOP 2015
Share-Based Payments
Maximum number of shares authorized				346,235	177,499	95,000