Common Stock (Narrative) (Details)	9 Months Ended
	Jan. 31, 2015 USD ($) Y M	Jan. 31, 2015 CAD
Common Stock 1	12.50%	12.50%
Common Stock 2	42	42
Common Stock 3	6,860,000	6,860,000
Common Stock 4	7,860,000	7,860,000
Common Stock 5	15.00%	15.00%
Common Stock 6	$ 0.78
Common Stock 7	1.12
Common Stock 8	0.63
Common Stock 9	0.79
Common Stock 10	332,356	332,356
Common Stock 11	67,892	67,892
Common Stock 12	$ 0.73
Common Stock 13	1.25
Common Stock 14	122,750	122,750
Common Stock 15	485,726	485,726
Common Stock 16	66,525
Common Stock 17	355,254
Common Stock 18	189,156
Common Stock 19	168,160
Common Stock 20	542,569
Common Stock 21	448,234
Common Stock 22	1,105,444
Common Stock 23	2.5	2.5
Common Stock 24	3,145,800	3,145,800
Common Stock 25	5,636,170
Common Stock 26		5,505,150
Common Stock 27	1.79
Common Stock 28		1.75
Common Stock 29		2.25
Common Stock 30	220,206	220,206
Common Stock 31		1.75
Common Stock 32	1,465,000	1,465,000
Common Stock 33		3,662,500
Common Stock 34	3,579,335
Common Stock 35		2.50
Common Stock 36	$ 2.44
Common Stock 37	$ 3.25
Common Stock 38	732,500	732,500
Common Stock 39	93,057
Common Stock 40	6.00%	6.00%
Common Stock 41	50.00%	50.00%
Common Stock 42	3.00%	3.00%
Common Stock 43	43,516
Common Stock 44	38,333
Common Stock 45	136,749	136,749
Common Stock 46	75,438	75,438
Common Stock 47	700,000	700,000
Common Stock 48	556,401	556,401
Common Stock 49	2,462,365	2,462,365
Common Stock 50	2,458,153	2,458,153
Common Stock 51	180,870	180,870
Common Stock 52	1.53
Common Stock 53		1.61
Common Stock 54	276,731
Common Stock 55	346,326	346,326
Common Stock 56	0.95
Common Stock 57		1.06
Common Stock 58	327,525
Common Stock 59	552,240	552,240
Common Stock 60	77,044	77,044
Common Stock 61	5.00%	5.00%
Common Stock 62	2,500,000	2,500,000
Common Stock 63	3,000,000	3,000,000
Common Stock 64	326,613	326,613
Common Stock 65	191,066	191,066
Common Stock 66	145,161	145,161
Common Stock 67	181,452	181,452
Common Stock 68	760,814	760,814
Common Stock 69	271,380
Common Stock 70	$ 242,905
Common Stock 71	1.46	1.46
Common Stock 72	1.81	1.81