Debt - Narrative (Details)				12 Months Ended
	Jan. 23, 2018 USD ($)	Jan. 22, 2018 USD ($)	Dec. 01, 2016 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Line of Credit Facility [Line Items]
Borrowings				$ 594,000,000
Amortization of debt issuance costs				2,423,000	$ 201,000	$ 0
Outstanding debt paid down				6,000,000	$ 0	$ 0
Term B Loan Facility | Credit Agreement
Line of Credit Facility [Line Items]
Borrowing capacity			$ 600,000,000
Term loan facility term (in years)			7 years
Debt Instrument, covenant, maximum ratio			1.50
Debt Instrument, covenant, minimum ratio			1.00
Quarterly payment as a percentage of principal			0.25%
Debt instrument, maturity date			Nov. 30, 2023
Borrowings			$ 600,000,000	$ 594,000,000
Interest rate				5.00%
Unamortized debt issuance costs				$ 14,300,000
Interest expense				28,300,000
Amortization of debt issuance costs				$ 2,400,000
Term B Loan Facility | Credit Agreement | Subsequent Event
Line of Credit Facility [Line Items]
Outstanding debt paid down	$ 100,000,000	$ 100,000,000
Reduction in borrowing rate		0.75%
Third party cost incurred	$ 1,100,000	$ 1,100,000
Term B Loan Facility | Credit Agreement | Base Rate | Effective Date Margin
Line of Credit Facility [Line Items]
Debt instrument, basis spread on variable rate			2.25%
Term B Loan Facility | Credit Agreement | Base Rate | Margin Subject to Debt Covenant
Line of Credit Facility [Line Items]
Debt instrument, basis spread on variable rate			2.00%
Term B Loan Facility | Credit Agreement | London Interbank Offered Rate (LIBOR) | Subsequent Event
Line of Credit Facility [Line Items]
Debt instrument, basis spread on variable rate		2.50%
Term B Loan Facility | Credit Agreement | London Interbank Offered Rate (LIBOR) | Effective Date Margin
Line of Credit Facility [Line Items]
Debt instrument, basis spread on variable rate			3.25%
Term B Loan Facility | Credit Agreement | London Interbank Offered Rate (LIBOR) | Margin Subject to Debt Covenant
Line of Credit Facility [Line Items]
Debt instrument, basis spread on variable rate			3.00%