Employee Benefit Plans - Schedule of Weighted Average and Target Allocations of Pension Assets (Details) - Pension	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Weighted average assets allocations, percentage	100.00%	100.00%
Domestic equities
Defined Benefit Plan Disclosure [Line Items]
Weighted average assets allocations, percentage	35.20%	38.10%
Foreign equities
Defined Benefit Plan Disclosure [Line Items]
Weighted average assets allocations, percentage	10.80%	13.90%
Fixed income
Defined Benefit Plan Disclosure [Line Items]
Weighted average assets allocations, percentage	42.30%	36.90%
Commingled real estate funds
Defined Benefit Plan Disclosure [Line Items]
Weighted average assets allocations, percentage	10.50%	9.30%
Money market mutual funds
Defined Benefit Plan Disclosure [Line Items]
Weighted average assets allocations, percentage	1.20%	1.80%
Minimum | Equities
Defined Benefit Plan Disclosure [Line Items]
Plan assets, target allocation, percent	40.00%
Minimum | Fixed income
Defined Benefit Plan Disclosure [Line Items]
Plan assets, target allocation, percent	40.00%
Minimum | Commingled real estate funds
Defined Benefit Plan Disclosure [Line Items]
Plan assets, target allocation, percent	0.00%
Minimum | Money market mutual funds
Defined Benefit Plan Disclosure [Line Items]
Plan assets, target allocation, percent	0.00%
Maximum | Equities
Defined Benefit Plan Disclosure [Line Items]
Plan assets, target allocation, percent	60.00%
Maximum | Fixed income
Defined Benefit Plan Disclosure [Line Items]
Plan assets, target allocation, percent	60.00%
Maximum | Commingled real estate funds
Defined Benefit Plan Disclosure [Line Items]
Plan assets, target allocation, percent	10.00%
Maximum | Money market mutual funds
Defined Benefit Plan Disclosure [Line Items]
Plan assets, target allocation, percent	15.00%