Long-term Debt and Other Financing (Details2) - Revolving Credit Facility [Member] - USD ($)	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Line of Credit Facility [Line Items]
Line of credit facility, maximum borrowing capacity	$ 1,350,000,000.0
Line of Credit Facility, Expiration Date	Mar. 31, 2019
Minimum amount of borrowing capacity for a fixed charge coverage ratio applies	$ 135,000,000.0
Outstanding borrowings on revolving credit facility	440,000,000.0	$ 450,000,000.0
Line of Credit Facility, Current Borrowing Capacity	1,331,300,000
Letters of credit, outstanding	71,500,000
Line of credit facility, remaining borrowing capacity	$ 819,800,000
Debt Instrument, Covenant Description	The Credit Facility contains customary restrictions, including limitations on, among other things, distributions and dividends, acquisitions and investments, dispositions, indebtedness, liens and affiliate transactions. The Credit Facility requires that we maintain a minimum fixed charge coverage ratio of one to one if availability under the Credit Facility is less than $135.0. The Credit Facility?s current availability significantly exceeds $135.0. Availability is calculated as the lesser of the Credit Facility commitments or eligible collateral after advance rates, less outstanding revolver borrowings and letters of credit. We do not expect any of these restrictions to affect or limit our ability to conduct business in the ordinary course. We secure our Credit Facility obligations with our inventory and accounts receivable, and the Credit Facility?s availability fluctuates monthly based on the varying levels of eligible collateral.