Employee Benefit Plans - Assumptions Used (Details)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Pension Benefits [Member]
Benefit Obligations:
Discount rate	4.00%	4.60%	3.80%
Expected return on assets	5.50%	6.55%	7.00%
Net Periodic Benefit Costs:
Discount rate	4.60%	3.80%	4.72%
Expected return on assets	6.55%	7.00%	7.25%
Other Post-retirement Benefits [Member]
Benefit Obligations:
Discount rate	3.99%	4.60%	3.85%
Net Periodic Benefit Costs:
Discount rate	4.60%	3.85%	4.74%