Acquisitions (Details) $ in Thousands			3 Months Ended		6 Months Ended	12 Months Ended
	Feb. 01, 2019 USD ($) Store	Dec. 01, 2018 USD ($) Store	Mar. 31, 2019 USD ($) Acquisition	Dec. 31, 2018 Acquisition	Mar. 31, 2020 USD ($) Store Acquisition	Sep. 30, 2019 USD ($) Acquisition
Acquisition [Abstract]
Number of acquisitions completed | Acquisition			2	1	0	5
Number of stores | Store					63
Allocation of Purchase Price Consideration to Assets Acquired and Liabilities Assumed [Abstract]
Goodwill					$ 113,059	$ 113,059
Slalom Shop [Member]
Acquisition [Abstract]
Number of stores | Store		2
Cash paid for acquisition		$ 1,600
Interest rate		5.00%
Notes payable term					3 years
Allocation of Purchase Price Consideration to Assets Acquired and Liabilities Assumed [Abstract]
Total purchase price		$ 7,900
Slalom Shop [Member] | Notes Payable to Seller [Member]
Acquisition [Abstract]
Note payable to seller						$ 5,100
Slalom Shop [Member] | Notes Payable to Seller at 5% [Member]
Acquisition [Abstract]
Note payable to seller		$ 1,300
Ocean Blue [Member]
Acquisition [Abstract]
Number of stores | Store	3
Cash paid for acquisition	$ 8,700
Interest rate	5.00%
Notes payable term					3 years
Allocation of Purchase Price Consideration to Assets Acquired and Liabilities Assumed [Abstract]
Total purchase price	$ 10,700
Ocean Blue [Member] | Notes Payable to Seller at 5% [Member]
Acquisition [Abstract]
Note payable to seller	1,900
Ocean Blue [Member] | Long-term Debt [Member]
Acquisition [Abstract]
Note payable to seller	8,500
Ray Clepper [Member]
Allocation of Purchase Price Consideration to Assets Acquired and Liabilities Assumed [Abstract]
Total purchase price	$ 300
Ocean Blue and Ray Clepper [Member]
Allocation of Purchase Price Consideration to Assets Acquired and Liabilities Assumed [Abstract]
Prepaid expenses			$ 100
Accounts receivable			135
Inventory			20,569
Property and equipment			33
Identifiable intangible assets			4,989
Goodwill			4,739
Liabilities assumed			(19,601)
Total purchase price			10,964
Slalom Shop, Ocean Blue and Ray Clepper [Member]
Allocation of Purchase Price Consideration to Assets Acquired and Liabilities Assumed [Abstract]
Prepaid expenses			126
Accounts receivable			135
Inventory			27,295
Property and equipment			36
Identifiable intangible assets			7,992
Goodwill			8,087
Liabilities assumed			(24,786)
Total purchase price			$ 18,885