Subsequent Events - Additional Information (Details) - Subsequent Event - Morgan Stanley Senior Funding, Inc - Credit Agreement	Feb. 19, 2019 USD ($)
Subsequent Event [Line Items]
Cash collateralized	$ 26,300,000
Borrowings under credit agreement	$ 0
Term Loan A Facility
Subsequent Event [Line Items]
Debt instrument term, years	4 years
Maximum borrowing capacity	$ 75,000,000
Debt instrument, amortization description	Loans under the Term Loan A Facility will amortize in equal quarterly installments beginning on the last day of the fiscal quarter ending after the date of the initial borrowing under the Term Loan A Facility, in an aggregate annual amount equal to (i) on or prior to December 31, 2021, 1.25% of the drawn principal amount of the Term Loan Facility and (ii) thereafter, 2.50% of the drawn principal amount of the Term Loan Facility, with any remaining balance payable on the maturity date of the Term Loan A Facility.
Term Loan A Facility \| On or Prior to December 31, 2021
Subsequent Event [Line Items]
Percentage of amortization on drawn principal amount	1.25%
Term Loan A Facility \| Thereafter December 31, 2021
Subsequent Event [Line Items]
Percentage of amortization on drawn principal amount	2.50%
Revolving Credit Facility
Subsequent Event [Line Items]
Debt instrument term, years	4 years
Maximum borrowing capacity	$ 75,000,000
Revolving Credit Facility \| Term Loan A Facility
Subsequent Event [Line Items]
Maximum borrowing capacity	$ 75,000,000
Interest payments description	Loans under the Credit Facility bear interest at a rate equal to, at the Company’s election (i) an alternate base rate, based upon the highest of (x) the prime rate, (y) the federal funds effective date plus ½ of 1% and (z) the one-month LIBOR plus 1%, in each case plus an applicable margin of up to 1% per annum, with step-downs based on its secured leverage ratio or (2) an adjusted one-, two-, three-, or six month LIBOR, at its election, plus an applicable margin of up to 2% per annum, with step-downs based on its secured leverage ratio.
Revolving Credit Facility \| Term Loan A Facility \| Maximum
Subsequent Event [Line Items]
Applicable margin with step-downs based on secured leverage ratio	1.00%
Revolving Credit Facility \| Term Loan A Facility \| Federal Funds Effective Rate
Subsequent Event [Line Items]
Basis spread on variable rate	0.50%
Revolving Credit Facility \| Term Loan A Facility \| One-month LIBOR
Subsequent Event [Line Items]
Basis spread on variable rate	1.00%
Revolving Credit Facility \| Term Loan A Facility \| Adjusted One-, Two-, Three-, or Six Month LIBOR \| Maximum
Subsequent Event [Line Items]
Applicable margin with step-downs based on secured leverage ratio	2.00%
Uncommitted Incremental Facility
Subsequent Event [Line Items]
Maximum borrowing capacity	$ 50,000,000
Debt to consolidated EBITDA, description	1.0x of our consolidated EBITDA for the most recently completed four fiscal quarter period
Uncommitted Incremental Facility \| Maximum
Subsequent Event [Line Items]
Secured leverage ratio	1.50%

Debt instrument amortization description.

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Debt instrument amortization percentage.

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Debt instrument basis spread on variable rate applicable margin.

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Debt instrument secured leverage ratio.

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Carrying amount as of the balance sheet date of cash collateral held for borrowed securities, for which the cash is restricted as to withdrawal or usage.

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Percentage points added to the reference rate to compute the variable rate on the debt instrument.

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Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Description of the interest rate for the amounts borrowed under the credit facility, including the terms and the method for determining the interest rate (for example, fixed or variable, LIBOR plus a percentage, increasing rate, timing of interest rate resets, remarketing provisions).

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Maximum amount borrowed under the credit facility at any time during the period.

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Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

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Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

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