Debt (Schedule of Long-term Debt) (Details) - USD ($)	Sep. 30, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Total debt	$ 1,058,200,000	$ 945,500,000
Debt issuance costs	(8,000,000)	(10,300,000)
Less: short-term debt and current portion of long-term debt	(42,300,000)	(42,000,000)
Long-term debt	1,015,900,000	903,500,000
Master note and security agreement
Debt Instrument [Line Items]
Total debt	101,100,000	123,600,000
Term loan A—$375.0 million maturing January 2021
Debt Instrument [Line Items]
Total debt	281,300,000	281,300,000
Face amount	375,000,000
Term loan B—$300.0 million maturing April 2021
Debt Instrument [Line Items]
Total debt	279,400,000	279,100,000
Face amount	300,000,000
Revolving credit facility—$725.0 million maturing January 2021
Debt Instrument [Line Items]
Total debt	136,100,000	0
Face amount	725,000,000
Senior unsecured notes—$300.0 million maturing May 2022
Debt Instrument [Line Items]
Total debt	243,500,000	243,500,000
Face amount	300,000,000
International term loan—$20.6 million
Debt Instrument [Line Items]
Total debt	10,300,000	14,900,000
Face amount	21,900,000
International revolving credit facility—$16.3 million
Debt Instrument [Line Items]
Total debt	11,500,000	9,800,000
Face amount	17,600,000
Equipment term loans
Debt Instrument [Line Items]
Total debt	2,000,000	2,400,000
Other
Debt Instrument [Line Items]
Total debt	$ 1,000,000	$ 1,200,000