Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Apr. 30, 2020	Apr. 30, 2019
Statement of Cash Flows [Abstract]
Net Income (Loss) Attributable to Parent	$ 534,374	$ 438,197
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization, including debt cost	76,756	63,709
Allowance for doubtful accounts	1,332	341
Equity in losses (earnings) of unconsolidated affiliates	1,918	(1,852)
Stock-based compensation	17,229	17,600
Gain on sale of property and equipment	(1,745)	(3,753)
Deferred income taxes	9,265	14,583
Changes in operating assets and liabilities:
Accounts receivable	19,102	(69,920)
Vehicle pooling costs	661	(15,026)
Inventories	1,209	(5,721)
Prepaid expenses and other current and non-current assets	6,268	(8,605)
Operating lease right-of-use assets and lease liabilities	221	0
Accounts payable and accrued liabilities	(15,636)	17,747
Deferred revenue	1,365	3,512
Income taxes receivable	(12,076)	(3,578)
Income taxes payable	9,168	7,304
Other liabilities	1,999	(1,042)
Net Cash Provided by (Used in) Operating Activities	650,968	453,496
Cash flows from investing activities:
Purchases of property and equipment	(487,730)	(259,336)
Proceeds from sale of property and equipment	2,153	17,928
Payments to Acquire Businesses, Net of Cash Acquired	3,268	745
Net Cash Provided by (Used in) Investing Activities	(488,845)	(242,153)
Cash flows from financing activities:
Proceeds from the exercise of stock options	55,656	17,261
Proceeds from the issuance of Employee Stock Purchase Plan shares	3,955	3,501
Repurchases of common stock	0	(364,997)
Payments for employee stock-based tax withholdings	102,191	45,594
Proceeds from (Repayments of) Lines of Credit	0	7,000
Net Cash Provided by (Used in) Financing Activities	(42,580)	(382,829)
Effect of foreign currency translation	525	(208)
Net increase (decrease) in cash and cash equivalents	120,068	(171,694)
Cash and cash equivalents at beginning of period	186,319	274,520
Cash and cash equivalents at end of period	306,387	102,826
Supplemental disclosure of cash flow information:
Interest Paid, Excluding Capitalized Interest, Operating Activities	14,514	14,700
Income taxes paid, net of refunds	$ 59,302	$ 60,926