Shareholders' equity (Tables)

12 Months Ended

Dec. 31, 2011

Shareholders' equity [Abstract]

Shares oustanding

Shares outstanding – Changes in common shares outstanding during the years ended December 31 were as follows:

	2011			2010			2009
Balance, beginning of year		51,338			51,189			51,131
Issued		499			410			237
Repurchased		(940	)		(167	)		(120	)
Retired		(71	)		(94	)		(59	)
Balance, end of year		50,826			51,338			51,189

Accumulated other comprehensive loss

Accumulated other comprehensive loss – The components of accumulated other comprehensive loss as of December 31 were as follows:

	2011			2010			2009
Postretirement and defined benefit pension plans:
Unrealized prior service credit	$	13,321		$	15,651		$	17,978
Unrealized net actuarial losses		(75,599	)		(68,343	)		(70,328	)
Postretirement and defined benefit pension plans, net of tax		(62,278	)		(52,692	)		(52,350	)
Loss on derivatives, net of tax(1)		(2,931	)		(4,522	)		(5,841	)
Net unrealized gain on marketable securities, net of tax		178			13			-
Currency translation adjustment		5,630			7,189			5,373
Accumulated other comprehensive loss	$	(59,401	)	$	(50,012	)	$	(52,818	)

(1) Relates to interest rate locks executed in 2004 and 2002. See Note 6 for further information regarding these financial instruments.