Long-Term Debt - Schedule Of Consolidated Total Or Net Leverage Ratio (Details) - Amended and Restated Credit Agreement [Member]	Jun. 30, 2017
December 31, 2017 [Member]
Debt Instrument [Line Items]
Maximum Consolidated Total Leverage Ratio	5.75
Maximum Consolidated Net Leverage Ratio	5.75
March 31, 2018 [Member]
Debt Instrument [Line Items]
Maximum Consolidated Total Leverage Ratio	5.50
Maximum Consolidated Net Leverage Ratio	5.50
June 30, 2018 [Member]
Debt Instrument [Line Items]
Maximum Consolidated Total Leverage Ratio	5.25
Maximum Consolidated Net Leverage Ratio	5.25
September 30, 2018 [Member]
Debt Instrument [Line Items]
Maximum Consolidated Total Leverage Ratio	5.00
Maximum Consolidated Net Leverage Ratio	5.00
December 31, 2018 Through and Including March 31, 2019 [Member]
Debt Instrument [Line Items]
Maximum Consolidated Total Leverage Ratio	4.50
Maximum Consolidated Net Leverage Ratio	4.50
June 30, 2019 Through and Including September 30, 2019 [Member]
Debt Instrument [Line Items]
Maximum Consolidated Total Leverage Ratio	4.25
Maximum Consolidated Net Leverage Ratio	4.25
December 31, 2019 [Member]
Debt Instrument [Line Items]
Maximum Consolidated Total Leverage Ratio	4.00
Maximum Consolidated Net Leverage Ratio	4.00
March 31, 2020 and Each Fiscal Quarter Thereafter [Member]
Debt Instrument [Line Items]
Maximum Consolidated Total Leverage Ratio	3.50
Maximum Consolidated Net Leverage Ratio	3.50