Share-based compensation (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Share-based compensation
Total	$ 4,904	$ 9,620	$ 9,441	$ 13,806
Cost of sales
Share-based compensation
Total	536	500	1,090	1,157
Research and development
Share-based compensation
Total	1,065	708	2,019	1,137
Selling, general, and administrative
Share-based compensation
Total	2,646	3,368	5,503	6,468
Restructuring
Share-based compensation
Total	$ 657	841	$ 829	841
Acquisition costs
Share-based compensation
Total		$ 4,203		$ 4,203
Restricted share awards | Minimum
Share-based compensation
Expiration term			1 year
Restricted share awards | Maximum
Share-based compensation
Expiration term			5 years
Stock options
Number of Shares
Outstanding at the beginning of the period (in shares)			1,394
Expired or forfeited (in shares)			(118)
Outstanding at the end of the period (in shares)	1,276		1,276
Weighted Average Exercise Price
Outstanding at the beginning of the period (in dollars per share)			$ 34.97
Expired or forfeited (in dollars per share)			37.42
Outstanding at the end of the period (in dollars per share)	$ 34.75		$ 34.75
Non-vested restricted shares and performance shares
Number of Shares
Outstanding at the beginning of the period (in shares)			1,880
Granted (in shares)			824
Performance award adjustments (in shares)			(5)
Vested (in shares)			(468)
Forfeited (in shares)			(109)
Outstanding at the end of the period (in shares)	2,122		2,122
Weighted Average Grant Date Fair Value
Outstanding at the beginning of the period (in dollars per share)			$ 25.41
Granted (in dollars per share)			19.39
Performance award adjustments (in dollars per share)			32.67
Vested (in dollars per share)			26.19
Forfeited (in dollars per share)			26.06
Outstanding at the end of the period (in dollars per share)	$ 22.85		$ 22.85