Schedule of Significant Assumptions of Other Postretirement Benefit Plan (Details) - Other Postretirement Benefit Cost |
9 Months Ended | 12 Months Ended |
|---|---|---|
Sep. 30, 2016 |
Dec. 31, 2015 |
|
| Defined Benefit Plan Disclosure [Line Items] | ||
| Weighted average assumptions used to determine benefit obligations, Discount rate | 3.66% | 4.67% |
| Weighted average assumptions used to determine benefit obligations, Expected return on plan assets | 5.37% | 5.20% |
| Weighted average assumptions used to determine benefit obligations, Medical trend rate | 6.50% | 6.50% |
| Weighted average assumptions used to determine benefit obligations, Medical trend rate next fiscal year | 7.00% | |
| Weighted average assumptions used to determine benefit obligations, Medical trend rate | 5.00% | 5.00% |
| Minimum | ||
| Defined Benefit Plan Disclosure [Line Items] | ||
| Weighted average assumptions used to determine benefit obligations, Year reaches Medical trend rate | 2021 | 2021 |