Employee Retirement Plans (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Current target allocations
Target allocations (as a percent)	100.00%	100.00%
Contributory retirement (401(k)) savings plans
Company contributions	$ 184	$ 156	$ 161
Plan
Employee retirement plans
Unfunded projected benefit obligation	275	10
Comprehensive income (loss), net of tax	81	197	64
Comprehensive income (loss), tax expense (benefit)	46	112	36
Contributions by the entity	0	0	151
Pension plan assets at the fair value
Fair value of assets	1,862	1,981	1,892
Change in projected benefit obligation:
Projected benefit obligation at beginning of year	1,991	2,182
Interest cost	87	77	89
Actuarial loss (gain) on plan assets	171	(159)
Benefits paid	(112)	(109)
Projected benefit obligation at end of year	2,137	1,991	2,182
Change in plan assets:
Fair value of plan assets at beginning of year	1,981	1,892
Employer contribution	0	0	151
Actual (loss) gain on plan assets	(7)	198
Benefits paid	(112)	(109)
Fair value of plan assets at end of year	1,862	1,981	1,892
Funded status
Underfunded status	(275)	(10)
Accumulated Benefit Obligation
Accumulated benefit obligation	2,137	1,991
Liability recognized on the consolidated balance sheets
Accrued benefit cost	275	10
Weighted-average assumptions used in the measurement of benefit obligation
Discount rate (as a percent)	3.75%	4.50%
Expected long-term return on plan assets (as a percent)	2.00%	7.00%
Components of the net periodic benefit cost
Interest cost	87	77	89
Expected return on plan assets	(38)	(128)	(119)
Amortization of net actuarial loss	65	80	84
Net periodic benefit cost	114	29	54
Expected benefit payments
2015	128
2016	127
2017	128
2018	133
2019	140
2020-2024	722
Plan | Level 1
Pension plan assets at the fair value
Fair value of assets	1,862	1,981
Change in plan assets:
Fair value of plan assets at end of year	1,862	1,981
Plan | Pooled equity funds
Current target allocations
Target allocations (as a percent)	0.00%	55.10%
Plan | Pooled equity funds | Level 1
Pension plan assets at the fair value
Fair value of assets		1,092
Change in plan assets:
Fair value of plan assets at end of year		1,092
Plan | Pooled fixed income funds
Current target allocations
Target allocations (as a percent)	42.10%	36.70%
Plan | Pooled fixed income funds | Level 1
Pension plan assets at the fair value
Fair value of assets	785	728
Change in plan assets:
Fair value of plan assets at end of year	785	728
Plan | Other investments
Current target allocations
Target allocations (as a percent)	0.00%	7.60%
Plan | Other investments | Level 1
Pension plan assets at the fair value
Fair value of assets		150
Change in plan assets:
Fair value of plan assets at end of year		150
Plan | Cash and cash equivalents
Current target allocations
Target allocations (as a percent)	57.90%	0.60%
Plan | Cash and cash equivalents | Level 1
Pension plan assets at the fair value
Fair value of assets	1,077	11
Change in plan assets:
Fair value of plan assets at end of year	$ 1,077	$ 11