Employee Benefits Supplemental Executive Retirement Plans and Long Term Incentive Plans (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Deferred Compensation Arrangement with Individual, Compensation Expense	$ 0.9	$ 0.5	$ 0.2
Holding Company SERP [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Benefit Obligation	8.1	8.8
Defined Benefit Plan, Net Periodic Benefit Cost	1.4	0.5	0.9
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	4.65%	3.90%	4.55%
Pacific Northwest SERP [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Benefit Obligation	2.7	3.4
Defined Benefit Plan, Net Periodic Benefit Cost	0.1	0.4	0.4
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	4.25%	3.95%	4.95%
Defined Benefit Plan, Cost of Providing Special or Contractual Termination Benefits Recognized During Period		1.2
KLS LTIP [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Deferred Compensation Arrangement with Individual, Recorded Liability	5.5	3.8
Deferred Compensation Arrangement with Individual, Compensation Expense	$ 1.7	$ 1.6	$ 1.2