CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY - CAD CAD in Millions	Total	Share capital [Member]	Additional paid-in capital [Member]	Accumulated other comprehensive loss [Member]	Retained earnings [Member]
Beginning Balance at Dec. 31, 2013	CAD 7,097	CAD 2,240	CAD 34	CAD (1,503)	CAD 6,326
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,476	0	0	0	1,476
Other comprehensive income (loss)	(716)	0	0	(716)	0
Dividends declared ($1.4000 per share for the years ended December 31, 2014, 2015, and 2016, respectively)	(241)	0	0	0	(241)
Effect of stock-based compensation expense	19	0	19	0	0
CP Common Shares repurchased	(2,089)	(136)	0	0	(1,953)
Shares issued under stock option plan (Note 19)	64	81	(17)	0	0
Ending Balance at Dec. 31, 2014	5,610	2,185	36	(2,219)	5,608
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,352	0	0	0	1,352
Other comprehensive income (loss)	742	0	0	742	0
Dividends declared ($1.4000 per share for the years ended December 31, 2014, 2015, and 2016, respectively)	(221)	0	0	0	(221)
Effect of stock-based compensation expense	17	0	17	0	0
CP Common Shares repurchased	(2,748)	(181)	0	0	(2,567)
Shares issued under stock option plan (Note 19)	44	54	(10)	0	0
Ending Balance at Dec. 31, 2015	4,796	2,058	43	(1,477)	4,172
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,599	0	0	0	1,599
Other comprehensive income (loss)	(322)	0	0	(322)	0
Dividends declared ($1.4000 per share for the years ended December 31, 2014, 2015, and 2016, respectively)	(274)	0	0	0	(274)
Effect of stock-based compensation expense	14	0	14	0	0
CP Common Shares repurchased	(1,210)	(84)	0	0	(1,126)
Shares issued under stock option plan (Note 19)	23	28	(5)	0	0
Ending Balance at Dec. 31, 2016	CAD 4,626	CAD 2,002	CAD 52	CAD (1,799)	CAD 4,371