Debt Debt - Interest Rates (Details)		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2016
Credit rating at least A- or A3 | Adjusted LIBOR rate loans and letter of credit | London Interbank Offered Rate (LIBOR)
Debt
Reference rate (as a percent)	0.85%
Credit rating at least BBBplus or BAA1 | Adjusted LIBOR rate loans and letter of credit | London Interbank Offered Rate (LIBOR)
Debt
Reference rate (as a percent)	0.90%
Credit rating at least BBB or BAA2 | Adjusted LIBOR rate loans and letter of credit | London Interbank Offered Rate (LIBOR)
Debt
Reference rate (as a percent)	1.00%
Credit rating at least BBB- or BAA3 | Adjusted LIBOR rate loans and letter of credit | London Interbank Offered Rate (LIBOR)
Debt
Reference rate (as a percent)	1.20%
Credit rating below BBB- or BAA3 | Adjusted LIBOR rate loans and letter of credit | London Interbank Offered Rate (LIBOR)
Debt
Reference rate (as a percent)	1.55%
Credit agreement | Credit rating at least A- or A3 | Base rate loans | Base rate
Debt
Reference rate (as a percent)		0.00%
Credit agreement | Credit rating at least BBBplus or BAA1 | Base rate loans | Base rate
Debt
Reference rate (as a percent)		0.00%
Credit agreement | Credit rating at least BBB or BAA2 | Base rate loans | Base rate
Debt
Reference rate (as a percent)		0.10%
Credit agreement | Credit rating at least BBB- or BAA3 | Base rate loans | Base rate
Debt
Reference rate (as a percent)		0.20%
Credit agreement | Credit rating below BBB- or BAA3 | Base rate loans | Base rate
Debt
Reference rate (as a percent)		0.60%
Term Loan [Member] | Credit rating at least A- or A3 | Base rate loans | Base rate
Debt
Reference rate (as a percent)		0.40%
Term Loan [Member] | Credit rating at least BBBplus or BAA1 | Base rate loans | Base rate
Debt
Reference rate (as a percent)		0.45%
Term Loan [Member] | Credit rating at least BBB or BAA2 | Base rate loans | Base rate
Debt
Reference rate (as a percent)		0.55%
Term Loan [Member] | Credit rating at least BBB- or BAA3 | Base rate loans | Base rate
Debt
Reference rate (as a percent)		0.80%
Term Loan [Member] | Credit rating below BBB- or BAA3 | Base rate loans | Base rate
Debt
Reference rate (as a percent)		1.25%