Employee Benefit Plans Money Market Pension Plan (MPPP) (Details) (Money Purchase Pension Plan [Member], USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014 year	Dec. 31, 2013	Dec. 31, 2012
Money Purchase Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Minimum qualifying age under plan	21
Service period	1 year
Minimum number of hours for allocation of an employer contribution	1000 hours
Employer contribution	6.50%
Additional contribution by employer	2.75%
Matching contributions vesting period	5 years
Expense attributable to the plan	$ 898	$ 1,000	$ 940