Financing Arrangements (Details 2) - USD ($) $ in Millions		12 Months Ended
	Feb. 12, 2016	Dec. 31, 2015	Dec. 31, 2014
Credit Agreement
Stand-by letters of credit outstanding		$ 24.8	$ 23.6
Debt outstanding		576.2	577.8
Prior Credit Agreement
Credit Agreement
Multi-currency borrowing capacity		$ 500.0	$ 500.0
Term of senior unsecured revolving credit facility		5 years	5 years
Potential additional borrowing capacity		$ 500.0	$ 500.0
Sublimit on letters of credit		100.0	$ 100.0
Unused and available credit under the credit agreement		200.2
Stand-by letters of credit outstanding		24.8
Debt outstanding		$ 275.0
Prior Eurocurrency rate loans | LIBOR
Credit Agreement
Variable interest rate basis		British Bankers Association LIBOR	British Bankers Association LIBOR
Prior base rate loans and swing line loans | LIBOR
Credit Agreement
Variable interest rate basis		British Bankers Association LIBOR	British Bankers Association LIBOR
Prior base rate loans and swing line loans | Federal funds
Credit Agreement
Variable interest rate basis		Federal Funds rate	Federal Funds rate
Credit Agreement | Subsequent event
Credit Agreement
Sublimit on letters of credit	$ 100.0
Eurocurrency rate loans | LIBOR | Subsequent event
Credit Agreement
Variable interest rate basis	British Bankers Association LIBOR
Eurocurrency rate loans | LIBOR | Minimum
Credit Agreement
Interest rate added to base rate (as a percent)		0.975%	0.975%
Eurocurrency rate loans | LIBOR | Minimum | Subsequent event
Credit Agreement
Interest rate added to base rate (as a percent)	0.975%
Eurocurrency rate loans | LIBOR | Maximum
Credit Agreement
Interest rate added to base rate (as a percent)	1.45%	1.45%	1.45%
Base rate loans and swing line loans | LIBOR
Credit Agreement
Interest rate added to base rate (as a percent)		1.00%	1.00%
Base rate loans and swing line loans | LIBOR | Subsequent event
Credit Agreement
Interest rate added to base rate (as a percent)	1.00%
Variable interest rate basis	British Bankers Association LIBOR
Base rate loans and swing line loans | LIBOR | Minimum
Credit Agreement
Interest rate added to base rate (as a percent)		0.00%	0.00%
Base rate loans and swing line loans | LIBOR | Minimum | Subsequent event
Credit Agreement
Interest rate added to base rate (as a percent)	0.00%
Base rate loans and swing line loans | LIBOR | Maximum
Credit Agreement
Interest rate added to base rate (as a percent)		0.45%	0.45%
Base rate loans and swing line loans | LIBOR | Maximum | Subsequent event
Credit Agreement
Interest rate added to base rate (as a percent)	0.45%
Base rate loans and swing line loans | Federal funds
Credit Agreement
Interest rate added to base rate (as a percent)		0.50%	0.50%
Base rate loans and swing line loans | Federal funds | Subsequent event
Credit Agreement
Interest rate added to base rate (as a percent)	0.50%
Variable interest rate basis	Federal funds rate
Base rate loans and swing line loans | Prime Rate
Credit Agreement
Variable interest rate basis		prime rate	prime rate
Base rate loans and swing line loans | Prime Rate | Subsequent event
Credit Agreement
Variable interest rate basis	prime rate
Senior unsecured revolving credit facility | Subsequent event
Credit Agreement
Multi-currency borrowing capacity	$ 500.0
Term of senior unsecured revolving credit facility	5 years
Term loan facility | Subsequent event
Credit Agreement
Term of senior unsecured revolving credit facility	5 years
Face Amount	$ 300.0
First year (as a percent)	0.00%
Second and third years (as a percent)	7.50%
Fourth and fifth years (as a percent)	10.00%
Term loan facility | LIBOR | Subsequent event
Credit Agreement
Variable interest rate basis	British Bankers Association LIBOR
Term loan facility | LIBOR | Minimum | Subsequent event
Credit Agreement
Interest rate added to base rate (as a percent)	1.125%
Term loan facility | LIBOR | Maximum | Subsequent event
Credit Agreement
Interest rate added to base rate (as a percent)	1.75%