Debt - Summary of Amounts Outstanding under the Credit Facility (Details) - USD ($) $ in Thousands	1 Months Ended	9 Months Ended
	May 31, 2018	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Line of Credit Facility [Line Items]
Debt Issuance Costs, Line of Credit Arrangements, Net		$ 5,292		$ 6,654
Repayments of Lines of Credit		150,751	$ 0
Revolving credit facility
Line of Credit Facility [Line Items]
Repayments of Lines of Credit	$ 115,000
Tranche A-1 and A-2 Loans [Member]
Line of Credit Facility [Line Items]
Debt, gross		300,000		50,000
Unamortized deferred financing costs, net		(3,019)		(3,463)
Debt, net		$ 296,981		46,537
Line of credit | Revolving credit facility
Line of Credit Facility [Line Items]
Interest Rate (1)		3.36%
Debt, net		$ 0		115,751
Letters of credit		$ 5,700		5,700
Line of credit | Tranche A-1 Term Loan
Line of Credit Facility [Line Items]
Interest Rate (1)		3.32%
Debt, gross		$ 100,000		50,000
Line of credit | Tranche A-2 Term Loan Credit Facility [Member]
Line of Credit Facility [Line Items]
Interest Rate (1)		3.81%
Debt, gross		$ 200,000		$ 0