Annual report pursuant to Section 13 and 15(d)

Commitments - Other Commitments Narrative (Details)

v3.8.0.1
Commitments - Other Commitments Narrative (Details) - Purchase commitments
$ in Thousands
Dec. 31, 2017
USD ($)
Business Combination, Separately Recognized Transactions [Line Items]  
2018 $ 39,330
Total $ 39,330