Pension Benefits (Tables)

12 Months Ended

Dec. 31, 2011

Pension Benefits [Abstract]

Changes in the benefit obligation and the fair value of the Benefit Plans assets

	Year Ended			Year Ended
	December 31, 2011			December 31, 2010
	$			$
Change in benefit obligation:
Beginning balance		120,723			114,256
Service cost		8,829			8,345
Interest cost		5,167			5,148
Contributions by plan participants		739			579
Actuarial loss		9,408			730
Benefits paid		(4,395	)		(7,333	)
Settlements and curtailments		—			(4,937	)
Foreign currency exchange rate changes		(3,299	)		3,635
Other		—			300
Ending balance		137,172			120,723
Change in fair value of plan assets:
Beginning balance		102,085			95,495
Actual return on plan assets		2,931			125
Contributions by the employer		12,061			11,649
Contributions by plan participants		739			579
Benefits paid		(4,339	)		(7,259	)
Settlements and curtailments		—			(1,314	)
Foreign currency exchange rate changes		(2,357	)		3,110
Other		(422	)		(300	)
Ending balance		110,698			102,085
Funded status deficiency		(26,474	)		(18,638	)
Amounts recognized in the balance sheets:
Other long-term liabilities		26,474			18,638
Accumulated other comprehensive (loss) income:
Net actuarial losses (1)		(19,929	)		(18,279	)

(1) As at December 31, 2011, the estimated amount that will be amortized from accumulated other comprehensive (loss) income into net periodic benefit cost in 2012 is $(0.2) million.

Pension plans with benefit obligations and accumulated benefit obligations in excess of plan assets

	December 31, 2011		December 31, 2010
	$		$
Benefit obligation		113,460		72,180
Fair value of plan assets		85,432		53,421
Accumulated benefit obligation		35,358		62,405
Fair value of plan assets		31,815		39,134

Components of net periodic pension cost relating to the Benefit Plans

	Year Ended December 31, 2011			Year Ended December 31, 2010			Year Ended December 31, 2009
	$			$			$
Net periodic pension cost:
Service cost		8,978			8,616			9,753
Interest cost		5,250			5,091			4,548
Expected return on plan assets		(5,805	)		(5,431	)		(4,624	)
Amortization of net actuarial loss		371			281			1,394
Other		421			(3,390	)		184
Net cost		9,215			5,167			11,255

Components of other comprehensive (income) loss relating to the Plans

	Year Ended December 31, 2011			Year Ended December 31, 2010		Year Ended December 31, 2009
	$			$		$
Other comprehensive (income) loss:
Net loss (gain) arising during the period		12,052			5,711		(13,524	)
Amortization of net actuarial (gain) loss		(319	)		1,026		(1,394	)
Other loss (gain)		—			390		(785	)
Total loss (income)		11,733			7,127		(15,703	)

Estimated future benefit payments which reflect expected future service to be paid by the Benefit Plans

	Pension Benefit
	Payments
Year	$
2012		8,000
2013		4,969
2014		6,361
2015		6,251
2016		5,704
2017—2021		29,263
Total		60,548

Fair value of the plan assets

	December 31, 2011		December 31, 2010
	$		$
Pooled Funds (1)		82,501		74,826
Mutual Funds (2)
Equity investments		13,852		13,073
Debt securities		3,445		3,197
Real estate		2,092		2,327
Cash and money market		291		1,034
Other		8,517		7,628
Total		110,698		102,085

(1) The Company has no control over the investment mix or strategy of the pooled funds. The pooled funds guarantee a minimum rate of return. If actual investment returns are less than the guarantee minimum rate, then the provider’s statutory reserves are used to top up the shortfall. The pooled funds primarily invest in hold to maturity bonds, real estate and other fixed income investments, which are expected to provide a stable rate of return.

(2) The mutual funds primary aim is to provide investors with an exposure to a diversified mix of predominantly growth oriented assets (70%) with moderate to high volatility and some defensive assets (30%).

Schedule of assumptions used

	December 31, 2011			December 31, 2010
Discount rates		3.2	%		4.4	%
Rate of compensation increase		4.4	%		4.6	%

	Year Ended December 31, 2011			Year Ended December 31, 2010			Year Ended December 31, 2009
Discount rates		3.2	%		4.4	%		5.0	%
Rate of compensation increase		4.4	%		4.6	%		4.7	%
Expected long-term rates of return (1)		5.0	%		5.7	%		6.0	%

(1) To the extent the expected return on plan assets varies from the actual return, an actuarial gain or loss results. The expected long-term rates of return on plan assets are based on the estimated weighted-average long-term returns of major asset classes. In determining asset class returns, the Company takes into account long-term returns of major asset classes, historical performance of plan assets, as well as the current interest rate environment. The asset class returns are weighted based on the target asset allocations.