Employee Retirement Plans - Pension expense (Details) $ in Thousands |
12 Months Ended | ||
|---|---|---|---|
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Dec. 31, 2018
USD ($)
item
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Dec. 31, 2017
USD ($)
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Dec. 31, 2016
USD ($)
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| Employee Retirement Plans | |||
| Number of regional multi-employer pension plans in which the entity participates | item | 37 | ||
| Defined contribution plans | $ 7,595 | $ 4,089 | $ 3,950 |
| Multi-employer plans | 11,224 | 8,677 | 6,593 |
| Total expense related to participation in retirement plans | $ 18,819 | $ 12,766 | $ 10,543 |
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- Definition Amount of expense related to multiemployer retirement plans. No definition available.
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- Definition Represents the number of regional multi-employer pension plans in which the entity participates. No definition available.
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- Definition The amount of expense related to Company's participation in retirement plans. No definition available.
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- References No definition available.
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- Definition Amount of cost for defined contribution plan. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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