Long-Term Debt (Narrative) (Details) - USD ($)						3 Months Ended	9 Months Ended		12 Months Ended
	Aug. 12, 2019	Jun. 10, 2019	Dec. 10, 2018	Aug. 07, 2018	Jul. 02, 2016	Sep. 30, 2019	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018	Jul. 01, 2016
Disclosure Long Term Debt Additional Information [Line Items]
Proceeds from issuance of long-term debt								$ 107,607,000
Long-term debt						$ 439,081,000	$ 439,081,000		$ 610,787,000
Line of credit facility, current borrowing capacity						24,400,000	24,400,000
Interest Rate Cap [Member]
Disclosure Long Term Debt Additional Information [Line Items]
Derivative Notional Amounts							300,000,000
Interest Rate Swap [Member]
Disclosure Long Term Debt Additional Information [Line Items]
Derivative Notional Amounts			$ 300,000,000						$ 300,000,000
Derivative, maturing in 2021							150,000,000
Derivative, maturing in 2022							150,000,000
Derivative loss						400,000	900,000
Other comprehensive income (loss) reclassification due to de-designation							$ 400,000
Revolving Credit Facility [Member]
Disclosure Long Term Debt Additional Information [Line Items]
Repayments of debt		$ 109,600,000
BoA Credit Agreement [Member]
Disclosure Long Term Debt Additional Information [Line Items]
Debt instrument period of credit agreement				5 years
Proceeds from issuance of long-term debt					$ 335,000,000
Debt instrument covenant payment percentage of intellectual property disposed liquidation value							50.00%
Debt instrument covenant payment percentage of net proceeds related to other assets constituting collateral							100.00%
Debt instrument orderly liquidation value of registered trademarks percentage benchmark							15.00%
Debt instrument, covenant description							(i) maintain a positive net income, (ii) satisfy a maximum loan to value ratio initially set at 50.0% (applicable to the Amended Revolving Loans and Amended Tranche A Loans) decreasing over the term of the Amended BoA Credit Agreement until reaching a final maximum loan to value ratio of 42.5% and (iii) satisfy a maximum consolidated first lien leverage ratio, initially set at 3.875:1:00, decreasing over the term of the Amended BoA Credit Agreement until reaching a final maximum ratio of 2.875:1.00 for the fiscal quarter ending September 30, 2022 and thereafter.
Debt instrument, description							(i) the loans outstanding under the Amended BoA Credit Agreement plus, (a) where intellectual property is disposed, 50.0% of the disposed intellectual property's orderly liquidation value, and (b) where any other assets constituting collateral are disposed or upon the receipt of certain insurance proceeds, 100% of the net proceeds thereof, subject to certain reinvestment rights; and (ii) the Amended Tranche A-1 Loans to the extent that the outstanding principal amount thereof exceeds 15.0% of the orderly liquidation value of the registered trademarks owned by the BoA Facility Loan Parties.
Debt instrument, covenant compliance							At September 30, 2019, the Company is in compliance with the covenants included in the Amended BoA Credit Agreement.
BoA Term Loans [Member]
Disclosure Long Term Debt Additional Information [Line Items]
Debt instrument, periodic payment							$ 5,000,000
Debt instrument, date of first required payment							Sep. 30, 2016
Tranche A [Member]
Disclosure Long Term Debt Additional Information [Line Items]
Maximum loan to value ratio							50.00%
Tranche A [Member] | Revolving Credit Facility [Member]
Disclosure Long Term Debt Additional Information [Line Items]
Consolidated first lien leverage ratio							2.80%
Line of credit facility, covenant terms							(i) the Revolving Credit Facility and Tranche A Loans as would not cause the consolidated first lien leverage ratio, determined on a pro forma basis after giving effect to any such increase, to exceed 2.80:1.00 and (ii) the Tranche A-1 Loans, as would not cause the consolidated first lien leverage ratio, determined on a pro forma basis after giving effect to any such increase, to exceed (a) with respect to any increase, the proceeds of which will be used solely to finance an acquisition, 3.00:1.00 and (b) with respect to any other increase, 2.90:1.00, subject to the satisfaction of certain conditions in the Amended BoA Credit Agreement.
Tranche A -1 Term Loans [Member]
Disclosure Long Term Debt Additional Information [Line Items]
Deferred financing costs							$ 600,000
Repayments of debt		$ 44,400,000
Revolving Loans [Member]
Disclosure Long Term Debt Additional Information [Line Items]
Long-term debt										$ 115,000,000
Maximum loan to value ratio							50.00%
Revolving Loans [Member] | Notes Payable to Banks [Member] | London Interbank Offered Rate (LIBOR) [Member]
Disclosure Long Term Debt Additional Information [Line Items]
Debt instrument, basis spread on variable rate							3.50%
GSO Credit Agreement [Member]
Disclosure Long Term Debt Additional Information [Line Items]
Debt instrument, covenant description							(a) in the event the consolidated total leverage ratio was at least 4.00:1.00, 75% thereof, (b) in the event the consolidated total leverage ratio was less than 4.00:1.00 but at least 3.00:1.00, 50% thereof and (c) in the event the consolidated total leverage ratio was less than 3.00:1.00, 0% thereof.
Line of credit facility, interest rate description							(i) the LIBOR rate plus 8.75% per annum or (ii) the base rate plus 7.75% per annum.
Debt instrument, covenant compliance							At September 30, 2019, the Company is in compliance with the covenants included in the Amended FS/KKR Credit Agreement.
GSO Credit Agreement Reinvestment Rights Scenario Three [Member]
Disclosure Long Term Debt Additional Information [Line Items]
Debt instrument covenant payment percentage of net proceeds related to other assets constituting collateral							0.00%
Amended KKR Credit Agreement [Member] | Scenario Plan One [Member]
Disclosure Long Term Debt Additional Information [Line Items]
Debt instrument covenant payment percentage of net proceeds related to other assets constituting collateral							75.00%
Amended KKR Credit Agreement [Member] | Scenario Plan Two [Member]
Disclosure Long Term Debt Additional Information [Line Items]
Debt instrument covenant payment percentage of net proceeds related to other assets constituting collateral							50.00%
Amended FS/KKR Credit Agreement [Member] | August 2018 Debt Facilities Member
Disclosure Long Term Debt Additional Information [Line Items]
Quarterly amortization payments	$ 1,000,000
Netting of cash for calculating leverage ratio covenant	5,000,000
Amended FS/KKR Credit Agreement [Member] | Revolving Credit Facility [Member] | August 2018 Debt Facilities Member
Disclosure Long Term Debt Additional Information [Line Items]
Line of credit facility, maximum borrowing capacity	30,000,000
Deferred financing costs						$ 3,300,000
FS/KKR Credit Agreement [Member] | London Interbank Offered Rate (LIBOR) [Member]
Disclosure Long Term Debt Additional Information [Line Items]
Debt instrument, basis spread on variable rate							8.75%
FS/KKR Credit Agreement [Member] | Base Rate [Member]
Disclosure Long Term Debt Additional Information [Line Items]
Debt instrument, basis spread on variable rate							7.75%
FS/KKR Credit Agreement [Member] | Senior secured term loan facility
Disclosure Long Term Debt Additional Information [Line Items]
Debt instrument, face amount										314,000,000
Debt instrument consolidated total leverage ratio							6.00%
New Amended FS/KKR Credit Agreement [Member]
Disclosure Long Term Debt Additional Information [Line Items]
Quarterly amortization payments	$ 1,000,000
Debt instrument covenant payment percentage of intellectual property disposed liquidation value					50.00%
Debt instrument covenant payment percentage of net proceeds related to other assets constituting collateral					100.00%
Debt instrument, covenant description							(i) a maximum consolidated total leverage ratio, initially set at 7.25:1.00, decreasing over the term of the Amended FS/KKR Credit Agreement until reaching a final maximum ratio of 6.25:1.00 for the fiscal quarter ending September 30, 2022 and thereafter and (ii) a maximum consolidated first lien leverage ratio, initially set at 3.875:1.00, decreasing over the term of the Amended FS/KKR Credit Agreement until reaching a final maximum ratio of 2.875:1.00 for the fiscal quarter ending September 30, 2022 and thereafter
New Amended FS/KKR Credit Agreement [Member] | Scenario Plan One [Member]
Disclosure Long Term Debt Additional Information [Line Items]
Consolidated first lien leverage ratio							3.875%
Final consolidated total leverage ratio							7.25%
New Amended FS/KKR Credit Agreement [Member] | Scenario Plan Two [Member]
Disclosure Long Term Debt Additional Information [Line Items]
Consolidated first lien leverage ratio							2.875%
Final consolidated total leverage ratio							6.25%
New Amended FS/KKR Credit Agreement [Member] | Additional Loan Facility [Member] | Scenario Plan Three [Member]
Disclosure Long Term Debt Additional Information [Line Items]
Consolidated total leverage ratio							6.00%
Third Amended BoA Credit Agreement [Member]
Disclosure Long Term Debt Additional Information [Line Items]
Long-term debt										335,000,000
Amended BoA Revolving Credit Commitments [Member]
Disclosure Long Term Debt Additional Information [Line Items]
Line of credit facility, maximum borrowing capacity										130,000,000
Line of credit facility, unused capacity, commitment fee percentage							0.375%
Consolidated first lien leverage ratio				3.875%
Final consolidated first lien leverage ratio				2.875%
Third Amended BoA Tranche A-1 Loans [Member]
Disclosure Long Term Debt Additional Information [Line Items]
Debt instrument, face amount										70,000,000
Long-term debt										70,000,000
Third Amended BoA Tranche A-1 Loans [Member] | London Interbank Offered Rate (LIBOR) [Member]
Disclosure Long Term Debt Additional Information [Line Items]
Debt instrument, basis spread on variable rate							7.00%
Third Amended BoA Tranche A-1 Loans [Member] | Base Rate [Member]
Disclosure Long Term Debt Additional Information [Line Items]
Debt instrument, basis spread on variable rate							6.00%
Amended BoA Revolving Loans and Amended Tranche A Loans [Member] | London Interbank Offered Rate (LIBOR) [Member]
Disclosure Long Term Debt Additional Information [Line Items]
Debt instrument, basis spread on variable rate							3.50%
Amended BoA Revolving Loans and Amended Tranche A Loans [Member] | Base Rate [Member]
Disclosure Long Term Debt Additional Information [Line Items]
Debt instrument, basis spread on variable rate							2.50%
Third Amended BoA Tranche A Loans [Member]
Disclosure Long Term Debt Additional Information [Line Items]
Debt instrument, face amount										150,000,000
Long-term debt										$ 150,000,000
New Amended BoA Credit Agreement [Member]
Disclosure Long Term Debt Additional Information [Line Items]
Consolidated first lien leverage ratio							2.90%
Maximum | Tranche A [Member] | Scenario Plan One [Member]
Disclosure Long Term Debt Additional Information [Line Items]
Consolidated first lien leverage ratio							2.80%
Maximum | Amended KKR Credit Agreement [Member] | Scenario Plan Two [Member]
Disclosure Long Term Debt Additional Information [Line Items]
Debt instrument consolidated total leverage ratio							4.00%
Maximum | Amended KKR Credit Agreement [Member] | Scenario Plan Three [Member]
Disclosure Long Term Debt Additional Information [Line Items]
Debt instrument consolidated total leverage ratio							3.00%
Maximum | Third Amended BoA Credit Agreement [Member]
Disclosure Long Term Debt Additional Information [Line Items]
Maximum loan to value ratio				42.50%
Maximum | Third Amended BoA Tranche A-1 Loans [Member] | London Interbank Offered Rate (LIBOR) [Member]
Disclosure Long Term Debt Additional Information [Line Items]
Debt instrument, basis spread on variable rate				6.00%
Maximum | Third Amended BoA Tranche A-1 Loans [Member] | Base Rate [Member]
Disclosure Long Term Debt Additional Information [Line Items]
Debt instrument, basis spread on variable rate				5.00%
Maximum | Amended BoA Revolving Loans and Amended Tranche A Loans [Member] | London Interbank Offered Rate (LIBOR) [Member]
Disclosure Long Term Debt Additional Information [Line Items]
Debt instrument, basis spread on variable rate				3.00%
Maximum | Amended BoA Revolving Loans and Amended Tranche A Loans [Member] | Base Rate [Member]
Disclosure Long Term Debt Additional Information [Line Items]
Debt instrument, basis spread on variable rate				2.00%
Minimum [Member] | Tranche A -1 Term Loans [Member]
Disclosure Long Term Debt Additional Information [Line Items]
Consolidated first lien leverage ratio							3.00%
Minimum [Member] | Amended KKR Credit Agreement [Member] | Scenario Plan One [Member]
Disclosure Long Term Debt Additional Information [Line Items]
Debt instrument consolidated total leverage ratio							4.00%
Minimum [Member] | Amended KKR Credit Agreement [Member] | Scenario Plan Three [Member]
Disclosure Long Term Debt Additional Information [Line Items]
Debt instrument consolidated total leverage ratio							3.00%