Debt - Schedule of Debt and Capital Lease Obligations (Parenthetical) (Details)	6 Months Ended
	Jun. 30, 2017
4.7% senior notes due 2025
Debt Instrument [Line Items]
Debt instrument, interest rate	4.70%
Debt instrument, maturity year	2025
Senior unsecured credit facility- revolving loan due 2021
Debt Instrument [Line Items]
Debt instrument, maturity year	2021
3.95% senior notes due 2027
Debt Instrument [Line Items]
Debt instrument, interest rate	3.95%
Debt instrument, maturity year	2027