Employee Benefit Plans - Assumptions Used in Calculations (Details)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Pension
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Benefit Obligation [Abstract]
Discount rate, percent	4.01%	4.20%	3.80%
Rate of compensation, percent	4.16%	4.50%	4.50%
Assumptions used to determine net periodic benefit cost for years ended December 31:
Discount rate (pre-spin off), percent	0.00%	0.00%	4.60%
Discount rate (post-spin off), percent	4.20%	3.80%	4.04%
Expected long-term return on plan assets, percent	7.70%	7.70%	8.50%
Rate of compensation increase, percent	4.16%	4.50%	4.50%
Postretirement
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Benefit Obligation [Abstract]
Discount rate, percent	4.12%	4.34%	3.96%
Rate of compensation, percent	4.50%	4.50%	4.50%
Assumptions used to determine net periodic benefit cost for years ended December 31:
Discount rate (pre-spin off), percent	0.00%	0.00%	4.60%
Discount rate (post-spin off), percent	4.34%	3.96%	4.00%
Expected long-term return on plan assets, percent	0.00%	0.00%	0.00%
Rate of compensation increase, percent	4.50%	4.50%	4.50%