Pension and Employee Benefit Plans - Fair value of Funded Plan assets by major category (Details) $ in Thousands	Dec. 31, 2018 USD ($)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	$ 12,595
Money market fund
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	1,033
Mutual funds
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	4,881
Corporate stocks
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	4,465
Exchange traded funds
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	2,216
Level 1
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	11,562
Level 1 | Money market fund
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	0
Level 1 | Mutual funds
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	4,881
Level 1 | Corporate stocks
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	4,465
Level 1 | Exchange traded funds
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	2,216
Level 2
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	1,033
Level 2 | Money market fund
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	1,033
Level 2 | Mutual funds
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	0
Level 2 | Corporate stocks
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	0
Level 2 | Exchange traded funds
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	0
Level 3
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	0
Level 3 | Money market fund
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	0
Level 3 | Mutual funds
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	0
Level 3 | Corporate stocks
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	0
Level 3 | Exchange traded funds
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	$ 0