Employee benefits (Tables)

12 Months Ended

Dec. 31, 2017

Employee benefits

Schedule of employee benefit liabilities

	December 31,		December 31,
	2017		2016
Salary and benefits payable	$	112.7	$	80.7
Share-based payment plans		13.7		5.3
Pension and other post-retirement benefits		215.1		241.5
Employee benefits		341.5		327.5
Current portion		(123.9)		(89.4)
	$	217.6	$	238.1

Schedule of plan assets

	December 31,		December 31,
	2017		2016
Cash and cash equivalents	$	6.0	$	3.4
Canadian equity securities		18.8		18.0
U.S. equity securities		13.6		13.0
Global equity securities		0.5		0.4
Government bonds		7.8		6.7
Corporate bonds		6.5		7.0
Pooled fund units:
Equity funds		264.4		221.9
Fixed income funds		152.9		159.2
Real estate funds		7.9		7.7
Total pension plan assets	$	478.4	$	437.3

Weighted-average of the principle actuarial assumptions

	December 31,		December 31,
	2017		2016
Discount rate	3.4	%	3.9	%
Future salary increases	3.25% - 3.75	%	3.5	%
Health care trends	6.75	%	4.5	%
Longevity at age 65 for current pensioners:
Males	20.9		20.9
Females	22.9		23.0
Longevity at age 65 for current pensioners aged 45:
Males	22.4		22.4
Females	24.3		24.5

Schedule of Sensitivity analysis

	Increase		Decrease
As at December 31, 2017	of 1%		of 1%
Discount rate	$	(78.3)	$	96.6
Future salary growth		0.2		(0.2)
Health care trends rate		3.2		(2.5)
Future mortality		(2.1)		2.1

Pension Plans

Employee benefits

Schedule of movement in net defined benefit liability

	Defined benefit				Fair value				Net defined benefit
	obligation				of plan assets				liability (asset)
	2017		2016		2017		2016		2017		2016
Defined benefit obligation as at January 1,	$	614.4	$	626.6	$	(437.3)	$	(457.9)	$	177.1	$	168.7
Included in earnings:
Current service cost		6.0		6.0		—		—		6.0		6.0
Past service costs		0.1		0.1		—		—		0.1		0.1
Liabilities extinguished/ assets distributed on settlement		—		(28.5)		—		23.7		—		(4.8)
Interest cost (income)		23.3		25.9		(16.4)		(19.0)		6.9		6.9
		29.4		3.5		(16.4)		4.7		13.0		8.2
Included in other comprehensive income:
Actuarial loss (gain) arising from:
- financial  assumptions		36.5		28.6		—		—		36.5		28.6
- demographic assumptions		(4.6)		(9.3)		—		—		(4.6)		(9.3)
- experience adjustment		6.0		(2.5)		—		—		6.0		(2.5)
Return on plan assets excluding interest income		—		—		(42.1)		(6.8)		(42.1)		(6.8)
Foreign exchange adjustment		5.2		2.0		(5.4)		(2.2)		(0.2)		(0.2)
		43.1		18.8		(47.5)		(9.0)		(4.4)		9.8
Other:
Employer contributions		—		—		(9.3)		(9.6)		(9.3)		(9.6)
Plan participant contributions		0.4		0.4		(0.4)		(0.4)		—		—
Benefit payments		(32.5)		(34.9)		32.5		34.9		—		—
		(32.1)		(34.5)		22.8		24.9		(9.3)		(9.6)
Defined benefit obligation as at December 31,	$	654.8	$	614.4	$	(478.4)	$	(437.3)	$	176.4	$	177.1

Other post-retirement plans

Employee benefits

Schedule of movement in net defined benefit liability

	Defined benefit				Fair value				Net defined benefit
	obligation				of plan assets				liability (asset)
	2017		2016		2017		2016		2017		2016
Defined benefit obligation as at January 1,	$	64.4	$	65.7	$	—	$	(0.4)	$	64.4	$	65.3
Included in earnings:
Current service cost		0.4		0.9		—		—		0.4		0.9
Past service costs		(25.8)		(1.9)		—		—		(25.8)		(1.9)
Interest cost (income)		2.3		2.6		—		—		2.3		2.6
		(23.1)		1.6		—		—		(23.1)		1.6
Included in other comprehensive income:
Actuarial loss (gain) arising from:
- financial assumptions		1.5		1.5		—		—		1.5		1.5
- demographic assumptions		(0.2)		1.7		—		—		(0.2)		1.7
- experience adjustment		(3.2)		(4.5)		—		—		(3.2)		(4.5)
Return on plan assets excluding interest income		—		—		—		—		—		—
Foreign exchange adjustment		1.4		0.6		—		—		1.4		0.6
		(0.5)		(0.7)		—		—		(0.5)		(0.7)
Other:
Employer contributions		—		—		(2.1)		(2.1)		(2.1)		(2.1)
Plan participant contributions		0.2		0.3		(0.2)		—		—		0.3
Benefit payments		(2.3)		(2.5)		2.3		2.5		—		—
		(2.1)		(2.2)		—		0.4		(2.1)		(1.8)
Defined benefit obligation as at December 31,	$	38.7	$	64.4	$	—	$	—	$	38.7	$	64.4