Employee Benefit Plans - Schedule of Multi-Employer Pension Plans Affecting Period-to-Period Comparability of Contributions (Details) - USD ($) $ in Thousands |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2018 |
Dec. 31, 2017 |
Dec. 31, 2016 |
|
| Retirement Benefits [Abstract] | |||
| Pension Fund | AI Pension Plan | ||
| EIN/Pension Plan Number | 941133245 | ||
| Pension Protection Act Zone Status | Red | Red | |
| FIP/RP Status | Implemented | ||
| Sonic Contributions | $ 176 | $ 171 | $ 150 |
| Surcharge Imposed | Yes | ||
| Collective-Bargaining Agreement Expiration Date | Between<br/>October 2021<br/>and February 2022 | ||
| X | ||||||||||
- Definition The Tax Identification Number (TIN), also known as an Employer Identification Number (EIN), is a unique 9-digit value assigned by the IRS. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- References No definition available.
|
| X | ||||||||||
- Definition Amount of contributions made to multiemployer plan by employer. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Definition Indicate the multiemployer plan's certified zone status as currently required by the Pension Protection Act of 2006 or a subsequent amendment thereof. The zone status categories are red (critical status), orange (seriously endangered), yellow (endangered), and green (none of the above). The acceptable values are "red", "orange", "yellow", "green", "other", and "NA". A multiemployer plan is a pension or postretirement benefit plan to which two or more unrelated employers contribute where assets contributed by one participating employer may be used to provide benefits to employees of other participating employers. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Definition Description of the significant collective-bargaining arrangements within the range of expiration dates for collective-bargaining arrangements requiring contributions to a multiemployer plan as well as other information to help investors understand the significance of the collective-bargaining agreements and when they expire. A multiemployer plan is a pension or postretirement benefit plan to which two or more unrelated employers contribute where assets contributed by one participating employer may be used to provide benefits to employees of other participating employers. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Definition Indicate whether a funding improvement plan or rehabilitation plan has been implemented or is pending for a pension or postretirement benefit plan to which two or more unrelated employers contribute where assets contributed by one participating employer may be used to provide benefits to employees of other participating employers. The acceptable values are "no", "pending", "implemented", "other", and "NA". Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Definition Description of the general nature of multiemployer plans and of the employer's participation in those plans that would indicate how the risks of participating in these plans are different from single-employer plans. A multiemployer plan is a pension or postretirement benefit plan to which two or more unrelated employers contribute where assets contributed by one participating employer may be used to provide benefits to employees of other participating employers. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Definition Indicate whether the employer paid a surcharge to the pension or postretirement benefit plan to which two or more unrelated employers contribute where assets contributed by one participating employer may be used to provide benefits to employees of other participating employers. The acceptable values are "no", "yes", and "NA". Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|