Restructuring Costs Narrative (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Dec. 31, 2015
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost		$ 8.1
Restructuring and Related Cost, Expected Cost Remaining	$ 0.1
One-time Termination Benefits [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost		5.3
Employee Relocation [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost		$ 2.8
Employee Relocation [Member] | Tulsa Regional Office [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	$ 0.3