XML 104 R51.htm IDEA: XBRL DOCUMENT v2.4.1.9

Stock-based compensation (Tables)

12 Months Ended

Dec. 31, 2014

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Schedule of stock-based compensation expenses included in general and administrative expenses

Stock-based compensation expenses included in general and administrative expenses are as follows:

Year ended December 31,		2014				2013
Share option plan (note 23(b))		$	921			$	981
Liability classified restricted share unit plan (note 23(d(i)))		790				2,652
Equity classified restricted share unit plan (note 23(d(ii)))		419				—
Performance restricted share unit plan (note 23(e))		94				—
Liability classified deferred stock unit plan (note 23(f(i)))		(1,100		)		2,560
Equity classified deferred stock unit plan (note 23(f(ii)))		2,181				—
		$	3,305			$	6,193

Schedule of stock options activity

		Number of options			Weighted average exercise price $ per share
Outstanding at December 31, 2012		3,029,734			5.70
Granted		177,400			5.91
Exercised(i)		(295,230	)		3.98
Forfeited		(698,624	)		7.12
Outstanding at December 31, 2013		2,213,280			5.51
Exercised(i)		(385,880	)		3.49
Forfeited		(61,480	)		7.83
Outstanding at December 31, 2014		1,765,920			5.87

(i) All stock options exercised resulted in new common shares being issued (note 17(a));

Summary of information about stock options outstanding

The following table summarizes information about stock options outstanding at December 31, 2014:

		Options outstanding									Options exercisable
Exercise price		Number			Weighted average remaining life		Weighted average exercise price				Number			Weighted average remaining life			Weighted average exercise price
$2.75		373,760			7.5 years		$	2.75			109,760			7.5 years			$	2.75
$2.79		450,000			7.5 years		$	2.79			—			—			$	—
$3.69		38,900			3.9 years		$	3.69			38,900			3.9 years			$	3.69
$4.90		40,000			7.3 years		$	4.90			16,000			7.3 years			$	4.90
$5.00		142,760			1.3 years		$	5.00			142,760			1.3 years			$	5.00
$5.91		166,600			9.0 years		$	5.91			33,320			9.0 years			$	5.91
$6.56		94,560			6.9 years		$	6.56			55,120			6.9 years			$	6.56
$8.28		60,000			4.5 years		$	8.28			60,000			4.5 years			$	8.28
$8.58		30,000			5.7 years		$	8.58			24,000			5.7 years			$	8.58
$9.33		71,580			5.1 years		$	9.33			59,840			5.1 years			$	9.33
$10.13		68,860			6.0 years		$	10.13			56,120			6.0 years			$	10.13
$13.21		75,000			3.0 years		$	13.21			75,000			3.0 years			$	13.21
$13.50		76,140			2.9 years		$	13.50			76,140			2.9 years			$	13.50
$16.46		50,000			3.3 years		$	16.46			50,000			3.3 years			$	16.46
$16.75		27,760			1.7 years		$	16.75			27,760			1.7 years			$	16.75
		1,765,920			6.1 years		$	5.87			824,720			4.5 years			$	8.41

Schedule of restricted share unit plan activity

		Number of units
Outstanding at December 31, 2012		1,110,275
Granted		555,204
Vested		(154,330	)
Forfeited		(487,205	)
Outstanding at December 31, 2013		1,023,944
Dividend equivalents granted		695
Vested		(350,271	)
Forfeited		(58,865	)
Outstanding at December 31, 2014		615,503

Equity classified restricted share unit plan

		Number of units			Weighted average exercise price $ per share
Outstanding at December 31, 2013		—			—
Granted		274,256			7.98
Dividend equivalents granted		11,557			6.15
Vested		(605	)		7.75
Forfeited		(22,300	)		7.87
Outstanding at December 31, 2014		262,908			7.91

Senior executive stock option plan

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Schedule of assumptions used to value stock option grants

The weighted average assumptions used in estimating the fair value of the fully vested senior executive stock options as at December 31, 2014 and 2013 are as follows:

Year ended December 31,		2014			2013
Number of senior executive stock options		258,200			550,000
Weighted average fair value per option granted ($)		0.08			1.71
Weighted average assumptions:
Dividend yield		2.20	%		N/A
Expected volatility		49.68	%		39.12	%
Risk-free interest rate		0.25	%		0.22	%
Expected life (years)		0.4			1.4

Deferred share unit plan

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Schedule of stock plan activity

Liability classified deferred stock unit plan

		Number of units
Outstanding at December 31, 2012		625,156
Issued		141,509
Redeemed		(179,831	)
Outstanding at December 31, 2013		586,834
Issued		7,674
Redeemed		(63,886	)
Outstanding at December 31, 2014		530,622

Equity classified deferred stock unit plan

		Number of units			Weighted average exercise price $ per share
Outstanding at December 31, 2013		—			—
Issued		161,007			6.52
Dividend equivalents granted		8,721			6.10
Outstanding at December 31, 2014		169,728			6.50

X

- Definition

Tabular disclosure of the amount of total share-based compensation cost, including the amounts attributable to each share-based compensation plan and any related tax benefits.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (h)(1)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

+ Details

Name:	us-gaap_ScheduleOfCompensationCostForShareBasedPaymentArrangementsAllocationOfShareBasedCompensationCostsByPlanTableTextBlock
Namespace Prefix:	us-gaap_
Data Type:	nonnum:textBlockItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Tabular disclosure of share-based compensation plans that may be presented in a single table for outstanding, vested and expected to vest, and exercisable awards. The information that may be disclosed in this table may include, but is not limited to, number of shares, weighted average exercise price, weighted average remaining contractual life, and aggregate intrinsic value.

+ References

No definition available.

+ Details

Name:	us-gaap_ScheduleOfShareBasedCompensationActivityTableTextBlock
Namespace Prefix:	us-gaap_
Data Type:	nonnum:textBlockItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Tabular disclosure of the number and weighted-average grant date fair value for restricted stock units that were outstanding at the beginning and end of the year, and the number of restricted stock units that were granted, vested, or forfeited during the year.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(1)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

+ Details

Name:	us-gaap_ScheduleOfShareBasedCompensationRestrictedStockUnitsAwardActivityTableTextBlock
Namespace Prefix:	us-gaap_
Data Type:	nonnum:textBlockItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Tabular disclosure of option exercise prices, by grouped ranges, including the upper and lower limits of the price range, the number of shares under option, weighted average exercise price and remaining contractual option terms.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

+ Details

Name:	us-gaap_ScheduleOfShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeTextBlock
Namespace Prefix:	us-gaap_
Data Type:	nonnum:textBlockItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Tabular disclosure of the number and weighted-average exercise prices (or conversion ratios) for share options (or share units) that were outstanding at the beginning and end of the year, vested and expected to vest, exercisable or convertible at the end of the year, and the number of share options or share units that were granted, exercised or converted, forfeited, and expired during the year.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(1)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

+ Details

Name:	us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock
Namespace Prefix:	us-gaap_
Data Type:	nonnum:textBlockItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Tabular disclosure of the significant assumptions used during the year to estimate the fair value of stock options, including, but not limited to: (a) expected term of share options and similar instruments, (b) expected volatility of the entity's shares, (c) expected dividends, (d) risk-free rate(s), and (e) discount for post-vesting restrictions.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (f)(2)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

+ Details

Name:	us-gaap_ScheduleOfShareBasedPaymentAwardStockOptionsValuationAssumptionsTableTextBlock
Namespace Prefix:	us-gaap_
Data Type:	nonnum:textBlockItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	us-gaap_PlanNameAxis=noa_DeferredShareUnitPlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_PlanNameAxis=noa_SeniorExecutiveStockOptionPlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: