Long-Term Debt - 2017 Credit Agreement (Details)	3 Months Ended	12 Months Ended
	Dec. 31, 2017 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018	Jun. 27, 2017 USD ($)
Debt Instrument [Line Items]
Loss on extinguishment of debt		$ 3,565,000
Maximum borrowing capacity					$ 30,000,000.0
Restricted payment basket			$ 15,000,000
Leverage ratio, maximum			4.50
Leverage ratio, maximum at maturity			4.00
Leverage ratio, minimum			1.00
2017 Term Loan Facility
Debt Instrument [Line Items]
Quarterly amortization payments	$ 1,500,000
Final payment amount	$ 559,500,000	$ 559,500,000
Interest rate			4.05%	4.77%
2017 Facilities
Debt Instrument [Line Items]
Number of times the available borrowing capacity may be increased					5
Increase limit					$ 75,000,000
2017 Revolving Credit Facility
Debt Instrument [Line Items]
Interest rate			3.51%
Loans Payable | 2017 Credit Facility
Debt Instrument [Line Items]
Face amount of debt					600,000,000
Revolving Credit Facility | 2017 Revolving Credit Facility
Debt Instrument [Line Items]
Available borrowing capacity			$ 330,000,000
Revolving Credit Facility | Loans Payable | 2017 Credit Facility
Debt Instrument [Line Items]
Face amount of debt					$ 500,000,000