Consolidated Financial Statements Consolidated Financial Statements (Details) - USD ($) $ in Thousands	3 Months Ended			6 Months Ended
	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017	Jun. 30, 2016	Jan. 01, 2018
New Accounting Pronouncement, Early Adoption [Line Items]
Tax assessment reserve			$ 5,400
Increase (Decrease) in Other Accounts Payable and Accrued Liabilities	$ (18,540)		(7,586)
Tax Cuts and jobs act, income tax expense (benefit)		$ 139,200
Tax Cuts and jobs act, incomplete accounting, transition tax for accumulated foreign earnings, provisional income tax expense	600
Decrease in accounts receivable	(61,301)		(60,858)
Increase in operating expenses			7,300
Net cash provided by operating activities	(11,395)		18,495
Inventory, Net	(687,817)	$ (649,448)
Revenues	930,928		828,293
Gross Profit	405,809		363,083
Net income	129,416		115,764
Decrease In Receivables Due To Factoring	(11,000)		(27,100)
Difference between Revenue Guidance in Effect before and after Topic 606 [Member]
New Accounting Pronouncement, Early Adoption [Line Items]
Revenues	600
Gross Profit	400
Net income	$ 300
Accounting Standards Update 2014-09 [Member]
New Accounting Pronouncement, Early Adoption [Line Items]
Prepaid Expense and Other Assets					$ 4,400
Inventory, Net					1,700
Taxes Payable					600
Accounting Standards Update 2014-09 [Member] | Retained Earnings [Member]
New Accounting Pronouncement, Early Adoption [Line Items]
Cumulative effect					$ 2,100
Restatement Adjustment [Member]
New Accounting Pronouncement, Early Adoption [Line Items]
Increase (Decrease) in Other Accounts Payable and Accrued Liabilities				$ (3,200)
Net cash provided by operating activities			$ 5,400