Stock-based compensation (Tables)

12 Months Ended

Dec. 31, 2011

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Schedule of Share-based Compensation, Stock Options, Activity [Table Text Block]

Summary information for all stock option activity under the Company’s plans is as follows:

	Years Ended December 31,
	2011				2010				2009
	Options		Weighted- Average Exercise Price		Options		Weighted- Average Exercise Price		Options		Weighted- Average Exercise Price
	(Amounts in thousands)				(Amounts in thousands)				(Amounts in thousands)
Outstanding at beginning of year	4,850		$	20.46	5,090		$	20.40	5,271		$	20.37
Granted	1,761		19.12		664		15.70		690		18.02
Exercised	(523	)	13.88		(265	)	8.43		(274	)	7.80
Forfeited or expired	(196	)	23.33		(639	)	20.32		(597	)	23.13
Outstanding at end of year	5,892		$	20.55	4,850		$	20.46	5,090		$	20.40
Options exercisable at end of year	3,328		$	22.34	3,286		$	21.59	3,309		$	20.31

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]

The following table sets forth fair value per share information, including related assumptions, used to determine compensation cost for the Company’s non-qualified stock options consistent with the requirements of ASC Topic 718.

	Years Ended December 31,
	2011			2010			2009
Weighted-average fair value per share of options granted during the year	$	5.57		$	5.73		$	7.28
Weighted-average assumptions:
Expected stock price volatility	51.6		%	51.5		%	57.8		%
Risk-free interest rate	1.4		%	1.5		%	2.3		%
Expected option life (years)	6.2			4.6			4.5
Expected annual dividend yield	2.2		%	2.4		%	2.6		%

Schedule of Nonvested Share Activity [Table Text Block]

The following table summarizes the Company’s unvested stock option activity for the year ended December 31, 2011:

	Shares		Weighted- Average Exercise Price (per Share)
	(Amounts in thousands)
Unvested at January 1, 2011	1,564		$	18.08
Granted	1,761		19.12
Vested	(720	)	20.67
Forfeited	(40	)	18.84
Unvested at December 31, 2011	2,565		$	18.23

Schedule of Nonvested Restricted Stock Units Activity [Table Text Block]

The following table summarizes the Company’s unvested restricted stock unit activity for the year ended December 31, 2011:

	Units		Weighted- Average Grant Date Fair Value (per Unit)
	(Amounts in thousands)
Unvested at January 1, 2011	1,698		$	16.61
Granted	624		22.00
Vested	(601	)	16.56
Forfeited	(43	)	17.84
Unvested at December 31, 2011	1,678		$	18.60