Financing Arrangements - Variable Interest Rates (Details) - Existing Term Loan Facility	9 Months Ended
	Sep. 30, 2018
Eurodollar Spread
Debt Instrument [Line Items]
Basis spread on variable rate	5.00%
Eurodollar Spread | Moody's, B1 Rating | Standard & Poor's, B Plus Rating or higher
Debt Instrument [Line Items]
Basis spread on variable rate	4.25%
Eurodollar Spread | Moody's, B2 Rating | Standard & Poor's, B Rating
Debt Instrument [Line Items]
Basis spread on variable rate	4.75%
Eurodollar Spread | Moody's, B3 Rating | Standard & Poor's, B Minus or lower Rating
Debt Instrument [Line Items]
Basis spread on variable rate	5.50%
ABR Spread
Debt Instrument [Line Items]
Basis spread on variable rate	4.00%
ABR Spread | Moody's, B1 Rating | Standard & Poor's, B Plus Rating or higher
Debt Instrument [Line Items]
Basis spread on variable rate	3.25%
ABR Spread | Moody's, B2 Rating | Standard & Poor's, B Rating
Debt Instrument [Line Items]
Basis spread on variable rate	3.75%
ABR Spread | Moody's, B3 Rating | Standard & Poor's, B Minus or lower Rating
Debt Instrument [Line Items]
Basis spread on variable rate	4.50%