Employee Benefit Plans - Pension Plan (Details)
$ in Thousands |
12 Months Ended |
|
|
|
Dec. 31, 2016
USD ($)
item
|
Dec. 31, 2015
USD ($)
|
Dec. 31, 2014
USD ($)
|
Dec. 31, 2016
USD ($)
|
Dec. 31, 2015
USD ($)
|
| Employee Benefit Plans |
|
|
|
|
|
| Projected benefit obligation |
$ 20,931
|
$ 20,931
|
|
$ 20,631
|
$ 20,931
|
| Fair value of plan assets |
|
|
|
16,777
|
16,886
|
| Net unfunded pension liability |
|
|
|
3,854
|
4,045
|
| Components of net periodic benefit cost |
|
|
|
|
|
| Benefit obligation at beginning of year |
20,931
|
|
|
|
|
| Benefit obligation at end of year |
20,631
|
20,931
|
|
|
|
| Components of estimated future benefit payments |
|
|
|
|
|
| 2017 |
|
|
|
2,469
|
|
| 2018 |
|
|
|
841
|
|
| 2019 |
|
|
|
808
|
|
| 2020 |
|
|
|
1,273
|
|
| 2021 |
|
|
|
856
|
|
| 2022-2026 |
|
|
|
5,343
|
|
| Total |
|
|
|
11,590
|
|
| Pension Plans |
|
|
|
|
|
| Employee Benefit Plans |
|
|
|
|
|
| Projected benefit obligation |
20,931
|
23,615
|
$ 19,245
|
20,631
|
20,931
|
| Actual return on plan assets |
1,500
|
(200)
|
|
|
|
| Components of net periodic benefit cost |
|
|
|
|
|
| Benefit obligation at beginning of year |
20,931
|
23,615
|
19,245
|
|
|
| Interest cost |
780
|
801
|
804
|
|
|
| Actuarial loss (gain) |
778
|
(1,925)
|
5,151
|
|
|
| Benefits paid |
(1,858)
|
(1,560)
|
(1,585)
|
|
|
| Benefit obligation at end of year |
$ 20,631
|
20,931
|
$ 23,615
|
|
|
| Global Pension Plan |
|
|
|
|
|
| Employee Benefit Plans |
|
|
|
|
|
| Normal retirement age of employees | item |
65
|
|
|
|
|
| Projected benefit obligation |
$ 16,338
|
16,338
|
|
16,145
|
16,338
|
| Fair value of plan assets |
|
|
|
13,697
|
13,481
|
| Net unfunded pension liability |
|
|
|
2,448
|
2,857
|
| Components of net periodic benefit cost |
|
|
|
|
|
| Benefit obligation at beginning of year |
16,338
|
|
|
|
|
| Benefit obligation at end of year |
$ 16,145
|
$ 16,338
|
|
|
|
| Components of weighted-average actuarial assumptions |
|
|
|
|
|
| Discount rate |
3.80%
|
4.00%
|
3.60%
|
|
|
| Expected return on plan assets |
7.00%
|
7.00%
|
7.50%
|
|
|
| Components of estimated future benefit payments |
|
|
|
|
|
| Contributions made by the General Partner, the Partnership and its subsidiaries to the Pension Plans |
$ 300
|
$ 600
|
$ 200
|
|
|
| GMG Pension Plan |
|
|
|
|
|
| Employee Benefit Plans |
|
|
|
|
|
| Normal retirement age of employees | item |
65
|
|
|
|
|
| Projected benefit obligation |
$ 4,593
|
4,593
|
|
4,486
|
4,593
|
| Fair value of plan assets |
|
|
|
3,080
|
3,405
|
| Net unfunded pension liability |
|
|
|
$ 1,406
|
$ 1,188
|
| Components of net periodic benefit cost |
|
|
|
|
|
| Benefit obligation at beginning of year |
4,593
|
|
|
|
|
| Benefit obligation at end of year |
$ 4,486
|
$ 4,593
|
|
|
|
| Components of weighted-average actuarial assumptions |
|
|
|
|
|
| Discount rate |
4.10%
|
4.30%
|
3.60%
|
|
|
| Expected return on plan assets |
7.00%
|
7.00%
|
7.00%
|
|
|