Share-based payments (Tables)

12 Months Ended

Dec. 31, 2017

Summary of Movements in Number of Share Options Outstanding and Weighted Average Exercise Prices

Movements in the number of share options outstanding and their related weighted average exercise prices are as follows:


	2017				2016
	Weighted average exercise price Cdn$		Number of options		Weighted average exercise price Cdn$		Number of options
At January 1,		7.55		28,896,035		9.97		25,519,434
Regular options granted		4.43		5,804,535		3.24		9,101,164
Exercised		3.22		(242,648)		-		-
Forfeited		13.44		(4,735,349)		11.49		(5,724,563)
At December 31,		6.04		29,722,573		7.55		28,896,035

Summary of Range of Exercise Prices of Outstanding Share Options

At December 31, 2017, 18,583,426 share purchase options (December 31, 2016 – 18,164,617) with a weighted average exercise price of Cdn$7.34 (December 31, 2016 – Cdn$9.64) had vested and were exercisable. Options outstanding are as follows:


		December 31, 2017
		Total options outstanding						Exercisable options
Range of exercise price Cdn$		Shares		Weighted average remaining contractual life (years)		Weighted average exercise price Cdn$		Shares		Weighted average exercise price Cdn$

	$3.00 to $3.99		7,835,899		3.1		3.23		2,514,519		3.25
	$4.00 to $4.99		5,842,935		4.1		4.43		33,333		4.23
	$5.00 to $5.99		12,247		3.4		5.91		4,082		5.91
	$6.00 to $6.99		6,916,166		2.1		6.66		6,916,166		6.66
	$7.00 to $7.99		4,903,752		1.1		7.81		4,903,752		7.81
	$8.00 to $8.99		45,405		0.3		8.19		45,405		8.19
	$10.00 to $10.99		4,166,169		0.2		10.42		4,166,169		10.42


			29,722,573		2.3		6.04		18,583,426		7.34

Summary of Assumptions Used to Estimate the Fair Value of Options Granted

The assumptions used to estimate the fair value of options granted during the years ended December 31, 2017 and 2016 were:


	2017		2016

Risk-free interest rate (range) (%)		0.70 – 1.05		0.43
Expected volatility (range) (%)		60 – 65		55 – 63
Expected life (range) (years)		1.80 – 3.80		1.82 – 3.82
Expected dividends (CDN$)		0.02		0.02
Forfeiture rate (%)		11.0		11.0

Summary of Movements in Number of Share Options Outstanding

A summary of the status of the RSU plan and changes during the year is as follows:


	2017		2016
At January 1,		1,240,174		884,846
Granted		936,832		784,203
Redeemed		(349,842)		(335,339)
Forfeited		(121,068)		(93,536)
At December 31,		1,706,096		1,240,174