Pension Plans, Cash Flows (Details) - Noncontributory Defined-Benefit Pension Plan [Member] $ in Thousands |
12 Months Ended |
|---|---|
|
Dec. 31, 2016
USD ($)
| |
| Defined Benefit Plan Disclosure [Line Items] | |
| Expected employer future contributions | $ 4,000 |
| Summary of expected benefit payments [Abstract] | |
| 2017 | 8,253 |
| 2018 | 8,748 |
| 2019 | 9,047 |
| 2020 | 9,322 |
| 2021 | 9,314 |
| 2022 - 2026 | $ 49,252 |