Debt - Summary of Carrying Value of Debt (Parenthetical) (Details)	1 Months Ended	8 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2018 USD ($) Installment	Aug. 31, 2018	Sep. 30, 2018 Installment	Dec. 31, 2017 Installment
Minimum
Debt Instrument [Line Items]
EBITDA, trailing period			3 months
Maximum
Debt Instrument [Line Items]
EBITDA, trailing period			12 months
First Term Loan
Debt Instrument [Line Items]
Interest only-payments term			18 months	18 months
Interest-only payments maturity month and year			2019-03	2019-03
Number of equal monthly installments of principal and interest			36	36
Debt, maturity month and year			Mar. 31, 2022	Mar. 31, 2022
First Term Loan | Prime Rate
Debt Instrument [Line Items]
Debt, variable rate			0.25%	0.25%
Second Term Loan
Debt Instrument [Line Items]
Interest only-payments term			11 months	11 months
Interest-only payments maturity month and year			2018-10	2018-10
Number of equal monthly installments of principal and interest			47	47
Debt, maturity month and year			Sep. 30, 2022	Sep. 30, 2022
Second Term Loan | Achieved trailing six-month EBITDA of at least $1.0 million
Debt Instrument [Line Items]
Interest-only payments maturity month and year	2019-03
Number of equal monthly installments of principal and interest	42
EBITDA, trailing period	6 months
Second Term Loan | Minimum | Achieved trailing six-month EBITDA of at least $1.0 million
Debt Instrument [Line Items]
EBITDA | $	$ 1,000,000
Second Term Loan | Prime Rate
Debt Instrument [Line Items]
Debt, variable rate	0.25%	5.25%
Second Term Loan | Prime Rate | Achieved trailing six-month EBITDA of at least $1.0 million
Debt Instrument [Line Items]
Debt, variable rate	5.25%
Line of Credit
Debt Instrument [Line Items]
Debt, maturity month and year			Sep. 30, 2020