Employee Benefit Plans - Fair Value of Pension Plan Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 7,647	$ 8,428	$ 10,949	$ 10,870
Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	3,725	3,416
Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	3,922	5,012
Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Cash
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	780	675
Cash | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	780	675
Cash | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Cash | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Government sponsored entities | Fixed income securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,496	2,287
Government sponsored entities | Fixed income securities | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Government sponsored entities | Fixed income securities | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,496	2,287
Government sponsored entities | Fixed income securities | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Municipal bonds and notes | Fixed income securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,453	1,084
Municipal bonds and notes | Fixed income securities | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Municipal bonds and notes | Fixed income securities | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,453	1,084
Municipal bonds and notes | Fixed income securities | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Corporate bonds and notes | Fixed income securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	973	1,641
Corporate bonds and notes | Fixed income securities | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Corporate bonds and notes | Fixed income securities | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	973	1,641
Corporate bonds and notes | Fixed income securities | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
U.S. companies | Equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2,505	2,481
U.S. companies | Equity securities | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2,505	2,481
U.S. companies | Equity securities | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
U.S. companies | Equity securities | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Foreign companies | Equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	440	260
Foreign companies | Equity securities | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	440	260
Foreign companies | Equity securities | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Foreign companies | Equity securities | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 0	$ 0