Condensed Consolidated Statements of Stockholders' Equity (Unaudited) (Parenthetical) - $ / shares	3 Months Ended		6 Months Ended
	Jan. 31, 2018	Jan. 31, 2017	Jan. 31, 2018	Jan. 31, 2017
Statement of Stockholders' Equity [Abstract]
Dividends declared (in dollars per share)	$ 0.39	$ 0.34	$ 0.78	$ 0.68