Summary of significant accounting policies - Revenue recognition - Practical expedient (Details) |
6 Months Ended |
|---|---|
Jun. 30, 2019 | |
| Summary of significant accounting policies | |
| Practical expedient of financing component | true |
| Practical expedient of incremental cost | true |
| X | ||||||||||
- References No definition available.
|
| X | ||||||||||
- Definition Indicates (true false) whether practical expedient was elected not to adjust consideration for effect of financing component when transfer and customer payment for product or service occurs within one year or less. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Indicates (true false) whether practical expedient was elected to recognize incremental cost of obtaining contract as expense when incurred if amortization period would have been one year or less. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|