Employee Benefit Plans - Assumptions Used (Details)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 30, 2016	Sep. 30, 2016
Pension Benefits
Benefit Obligations:
Discount rate	3.30%	4.32%	4.00%	3.57%	4.32%
Expected return on assets	3.25%	6.00%	5.50%
Net Periodic Benefit Costs:
Discount rate	4.13%	4.05%	4.60%
Expected return on assets	3.57%	5.95%	6.55%
Other Post-retirement Benefits
Benefit Obligations:
Discount rate	3.98%	4.32%	3.99%
Net Periodic Benefit Costs:
Discount rate	4.29%	3.99%	4.60%
Expected return on assets	3.47%