Revenues - Performance Obligations and Contract Balances (Details) - USD ($) |
Jun. 30, 2018 |
Dec. 31, 2017 |
|---|---|---|
| Revenue from Contract with Customer [Abstract] | ||
| Contract liabilities | $ 15,000,000 | $ 15,000,000 |
| Contract assets | 0 | $ 0 |
| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2018-07-01 | ||
| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | ||
| Remaining performance obligation | $ 68,500,000 | |
| Contract term (greater than) | 2 years 6 months |
| X | ||||||||||
- Definition Amount, after allowance for credit loss, of right to consideration in exchange for good or service transferred to customer when right is conditioned on something other than passage of time. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Definition Amount of obligation to transfer good or service to customer for which consideration has been received or is receivable. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- References No definition available.
|
| X | ||||||||||
- Definition Amount of transaction price allocated to performance obligation that has not been recognized as revenue. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available.
|
| X | ||||||||||
- Definition Period in which remaining performance obligation is expected to be recognized as revenue, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Details
|