Financial Statement Information (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended			6 Months Ended
	Mar. 31, 2020	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Inventory [Line Items]
Inventories		$ 2,288,293			$ 2,288,293		$ 2,772,777
Accounts Receivable, Allowance for Credit Loss, Current		70,000			70,000		53,000
Accounts Receivable, Credit Loss Expense (Reversal)					24,000	$ 6,000
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accounts Receivable, Credit Loss Expense (Reversal)					24,000	6,000
Adoption of ASU 2016-13 (see Note 3)			$ (3,000)		(2,519)
Accounts Receivable, Allowance for Credit Loss, Current		$ 70,000			70,000		53,000
Decrease in Market Capitalization	40.00%
Amount that fair value exceeds carrying value	12.00%		12.00%
Increase in Market Capitalization		28.00%
Rent Reductions in Selling, General and Administrative Expenses		$ 2,000
Payments for Repurchase of Common Stock				$ 120,000	88,006	$ 190,762
Lease Payment Deferrals Classified in Other Current Liabilities					7,000
AftermarketAndRefurbishedProducts [Member]
Inventory [Line Items]
Inventories		1,895,922			1,895,922		2,297,895
SalvageAndRemanufacturedProducts [Member]
Inventory [Line Items]
Inventories		366,699			366,699		447,908
ManufacturedProducts [Member]
Inventory [Line Items]
Inventories		25,672			25,672		26,974
Inventory, Raw Materials and Supplies, Gross		18,000			18,000		17,000
Inventory, Work in Process, Gross		3,000			3,000		3,000
Inventory, Finished Goods, Gross		$ 4,000			$ 4,000		$ 6,000
Minimum [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Lessee Lease Renewal Term					1 year
Lessee Lease Renewal Term					1 year
Maximum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Lessee Lease Renewal Term					40 years
Lessee Lease Renewal Term					40 years
Accounting Standards Update 2016-13 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Adoption of ASU 2016-13 (see Note 3)			$ 3,000