Employee Benefit Plans - Money Purchase Pension Plan (MPPP) (Details) - Money Purchase Pension Plan [Member] $ in Thousands	12 Months Ended
	Dec. 31, 2016 USD ($) year	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
Defined Benefit Plan Disclosure [Line Items]
Minimum qualifying age under plan | year	21
Service period	1 year
Minimum number of hours for allocation of an employer contribution	1000 hours
Employer contribution	3.00%
Additional contribution by employer	2.75%
Matching contributions vesting period	5 years
Expense attributable to the plan | $	$ 545	$ 926	$ 898