Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Treasury Stock	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)
Beginning Balance (in shares) at Jul. 31, 2013		8,858,280	62,045,264
Beginning Balance at Jul. 31, 2013		$ (266,147)	$ 6,205	$ 198,838	$ 953,740	$ (22)
Net income	$ 179,002				179,002
Stock option and restricted stock activity (in shares)		1,831	101,313
Stock option and restricted stock activity		$ (101)	$ 10	3,674
Restricted stock unit activity (in shares)		20,766	63,852
Restricted stock unit activity		$ (1,205)	$ 6	758
Special dividend - $1.00 per common share					(53,290)
Cash dividends - $0.92 in 2014, $1.08 in 2015, $1.20 in 2016 per common share					(49,024)
Unrealized appreciation on investments, net of tax	22					$ 22
Stock compensation expense				5,231
Ending Balance (in shares) at Jul. 31, 2014		8,880,877	62,210,429
Ending Balance at Jul. 31, 2014		$ (267,453)	$ 6,221	208,501	1,030,428
Net income	199,385				199,385
Shares purchased (in shares)		1,000,000
Shares purchased		$ (60,000)
Stock option and restricted stock activity (in shares)			5,000
Stock option and restricted stock activity			$ 1	140
Restricted stock unit activity (in shares)		30,597	90,608
Restricted stock unit activity		$ (1,562)	$ 9	122
Cash dividends - $0.92 in 2014, $1.08 in 2015, $1.20 in 2016 per common share					(57,381)
Stock compensation expense				6,776
Ending Balance (in shares) at Jul. 31, 2015		9,911,474	62,306,037
Ending Balance at Jul. 31, 2015	1,065,187	$ (329,015)	$ 6,231	215,539	1,172,432
Net income	256,519				256,519
Restricted stock unit activity (in shares)		45,706	133,758
Restricted stock unit activity		$ (2,484)	$ 13	(430)
Cash dividends - $0.92 in 2014, $1.08 in 2015, $1.20 in 2016 per common share					(62,970)
Stock compensation expense				9,387
Ending Balance (in shares) at Jul. 31, 2016		9,957,180	62,439,795
Ending Balance at Jul. 31, 2016	$ 1,265,222	$ (331,499)	$ 6,244	$ 224,496	$ 1,365,981