Employee Retirement Plans - Pension expense (Details) $ in Thousands |
12 Months Ended | ||
|---|---|---|---|
|
Dec. 31, 2015
USD ($)
item
|
Dec. 31, 2014
USD ($)
|
Dec. 31, 2013
USD ($)
|
|
| Retirement Plans [Line Items] | |||
| Number of regional multi-employer pension plans in which the entity participates | item | 21 | ||
| Pension Expense | $ 9,280 | $ 7,497 | $ 6,688 |
| Defined-contribution plans | |||
| Retirement Plans [Line Items] | |||
| Pension Expense | 3,451 | 2,983 | 3,095 |
| Defined-benefit pension plans | |||
| Retirement Plans [Line Items] | |||
| Pension Expense | 26 | ||
| Multi-employer plans | |||
| Retirement Plans [Line Items] | |||
| Pension Expense | $ 5,829 | $ 4,514 | $ 3,567 |
| X | ||||||||||
- Definition Represents the number of regional multi-employer pension plans in which the entity participates. No definition available.
|
| 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 The amount of pension benefit costs recognized during the period for (1) defined benefit plans and (2) defined contribution plans. For defined benefit plans, pension expense includes the following components: service cost, interest cost, expected return on plan assets, gain (loss) on plan assets, prior service cost or credit, transition asset or obligation, and gain (loss) due to settlements or curtailments. For defined contribution plans, the pension expense generally equals the firm's contribution to employees' accounts (if the firm contributes) during the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Details
|
| X | ||||||||||
- Details
|
| X | ||||||||||
- Details
|