Employee Benefit Plans Employee Benefit Plans - Various (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Components of net periodic pension expense:
Interest cost	$ 2,360	$ 2,112	$ 2,206
Expected return on plan assets	(3,105)	(2,705)	(2,648)
Amortization of net loss	320	1,348	974
Total net periodic pension (income) expense	(425)	755	532
Change in projected benefit obligation:
Projected benefit obligation at beginning of year	50,684	57,268
Interest cost	2,360	2,112	2,206
Benefits paid	(1,876)	(1,813)
Actuarial losses (gains)	10,939	(6,883)
Projected benefit obligation at year end	62,107	50,684	57,268
Change in plan assets:
Fair value of plan assets at beginning of year	42,965	37,941
Actual return	2,160	6,202
Employer contributions	1,938	635
Benefits paid	(1,876)	(1,813)
Fair value of plan assets at year end	45,187	42,965	37,941
Funded status (Accrued pension liabilities)	(16,920)	(7,719)
Unrecognized actuarial loss recognized in accumulated other comprehensive (loss) income	19,814	8,250
Defined Benefit Plan, Amortization of Net Gains (Losses)	1,429
Assumptions used to determine benefit obligation at year end:
Discount rate	3.75%	4.75%	3.75%
Assumptions used to determine net periodic benefit cost:
Discount rate	4.75%	3.75%	4.50%
Expected long-term weighted-average rate of return on plan assets	7.25%	7.25%	7.75%
Expected future benefit payments
Defined Benefit Plan, Expected Future Benefit Payments, Next Twelve Months	2,100
Defined Benefit Plan, Expected Future Benefit Payments, Year Two	2,300
Defined Benefit Plan, Expected Future Benefit Payments, Year Three	2,400
Defined Benefit Plan, Expected Future Benefit Payments, Year Four	2,600
Defined Benefit Plan, Expected Future Benefit Payments, Year Five	2,800
In aggregate during five years thereafter	15,800
Multiemployer Plan, Period Contributions	992	908	760
Defined contribution expense	10,773	9,814	8,011
Deferred Compensation Arrangement with Individual, Compensation Expense	$ 409	$ 276	$ 507