Stockholders' Equity (Schedule of Dividend Increases) (Details) (USD $)	1 Months Ended
	Apr. 30, 2014	Jul. 31, 2013	Apr. 30, 2013	Apr. 30, 2012
Schedule of Dividend Increases [Line Items]
Percent increase in common stock dividend	39.00%	100.00%	20.00%	25.00%
Quarterly [Member]
Schedule of Dividend Increases [Line Items]
Common stock cash dividend per share	0.25	0.18	0.09	0.075
Annual [Member]
Schedule of Dividend Increases [Line Items]
Common stock cash dividend per share	1	0.72	0.36	0.30