Debt And Financing - Price Grid (Details) - Credit Agreement Amendment, July 26, 2017	12 Months Ended
	Dec. 31, 2017
Leverage Ratios [Abstract]
December 31, 2017	3.50
March 31, 2018	3.50
June 30, 2018	3.50
September 30, 2018	3.50
December 31, 2018	3.50
March 31, 2019	3.25
June 30, 2019	3.25
September 30, 2019	3.25
December 31, 2019	3.00
March 31, 2020	3
June 30, 2020	3
September 30, 2020	2.75
December 31, 2020	2.75
March 31, 2021	2.75
June 30, 2021 and thereafter	2.50
Total Leverage Ratio	3.38