Employee Benefit Plans - Major Categories of Assets in Pension Plan (Details) - DB Pension Plans - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Total Fair Value of Plan Assets	$ 72,474	$ 80,154	$ 71,807
(Level 1)
Defined Benefit Plan Disclosure [Line Items]
Total Fair Value of Plan Assets	72,474	80,154
(Level 2)
Defined Benefit Plan Disclosure [Line Items]
Total Fair Value of Plan Assets	0	0
(Level 3)
Defined Benefit Plan Disclosure [Line Items]
Total Fair Value of Plan Assets	0	0
Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Total Fair Value of Plan Assets	1,018	448
Cash and cash equivalents | (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Total Fair Value of Plan Assets	1,018	448
Cash and cash equivalents | (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Total Fair Value of Plan Assets	0	0
Cash and cash equivalents | (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Total Fair Value of Plan Assets	0	0
Defined Benefit Plan, Equity Securities, Common Stock [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Fair Value of Plan Assets	20,648	24,994
Defined Benefit Plan, Equity Securities, Common Stock [Member] | (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Total Fair Value of Plan Assets	20,648	24,994
Defined Benefit Plan, Equity Securities, Common Stock [Member] | (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Total Fair Value of Plan Assets	0	0
Defined Benefit Plan, Equity Securities, Common Stock [Member] | (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Total Fair Value of Plan Assets	0	0
Mutual funds
Defined Benefit Plan Disclosure [Line Items]
Total Fair Value of Plan Assets	50,808	54,712
Mutual funds | (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Total Fair Value of Plan Assets	50,808	54,712
Mutual funds | (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Total Fair Value of Plan Assets	0	0
Mutual funds | (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Total Fair Value of Plan Assets	$ 0	$ 0