Condensed Consolidated Statements of Stockholders' Equity (Unaudited) (Parenthetical) - $ / shares	3 Months Ended		6 Months Ended
	Jan. 31, 2017	Jan. 31, 2016	Jan. 31, 2017	Jan. 31, 2016
Statement of Stockholders' Equity [Abstract]
Dividends declared per common share (in USD per share)	$ 0.34	$ 0.30	$ 0.68	$ 0.60