Debt - Interest Rates (Details)	12 Months Ended
	Dec. 31, 2018
Revolving Credit Facility | Credit Agreement — Revolving Credit Facility | Eurocurrency Rate
Debt Instrument [Line Items]
Interest rate	1.30%
Revolving Credit Facility | Credit Agreement — Revolving Credit Facility | Eurocurrency Rate | Minimum
Debt Instrument [Line Items]
Margin on variable interest rate	1.00%
Revolving Credit Facility | Credit Agreement — Revolving Credit Facility | Eurocurrency Rate | Maximum
Debt Instrument [Line Items]
Margin on variable interest rate	1.60%
Revolving Credit Facility | Credit Agreement — Revolving Credit Facility | Base Rate
Debt Instrument [Line Items]
Interest rate	0.30%
Revolving Credit Facility | Credit Agreement — Revolving Credit Facility | Base Rate | Minimum
Debt Instrument [Line Items]
Margin on variable interest rate	0.00%
Revolving Credit Facility | Credit Agreement — Revolving Credit Facility | Base Rate | Maximum
Debt Instrument [Line Items]
Margin on variable interest rate	0.60%
Term Loan Facility | Credit Agreement — Term Loan Facility | Eurocurrency Rate
Debt Instrument [Line Items]
Interest rate	1.50%
Term Loan Facility | Credit Agreement — Term Loan Facility | Eurocurrency Rate | Minimum
Debt Instrument [Line Items]
Margin on variable interest rate	1.125%
Term Loan Facility | Credit Agreement — Term Loan Facility | Eurocurrency Rate | Maximum
Debt Instrument [Line Items]
Margin on variable interest rate	1.90%
Term Loan Facility | Credit Agreement — Term Loan Facility | Base Rate
Debt Instrument [Line Items]
Interest rate	0.50%
Term Loan Facility | Credit Agreement — Term Loan Facility | Base Rate | Minimum
Debt Instrument [Line Items]
Margin on variable interest rate	0.125%
Term Loan Facility | Credit Agreement — Term Loan Facility | Base Rate | Maximum
Debt Instrument [Line Items]
Margin on variable interest rate	0.90%