Stock-based compensation (Tables)

3 Months Ended

Mar. 31, 2013

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

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.

	Three Months Ended
	March 31,
	2013			2012
Weighted-average fair value per share of options granted during the period	$	6.67		$	6.36
Weighted-average assumptions:
Expected stock price volatility	34.2		%	48.0		%
Risk-free interest rate	0.8		%	1.0		%
Expected option life (years)	5.0			4.8
Expected annual dividend yield	1.9		%	2.5		%

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

Stock option activity during the three months ended March 31, 2013 was as follows:

	Options (In Thousands)		Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (Years)	Aggregate Intrinsic Value (In Thousands)
Outstanding at December 31, 2012	6,958		$	19.94
Granted	12		26.26
Exercised	(133	)	15.05
Forfeited or expired	(18	)	17.65
Outstanding at March 31, 2013	6,819		$	20.05	6.6	$	47,195
Exercisable at March 31, 2013	3,137		$	22.79	4.1	$	15,729

Schedule of Nonvested Share Activity [Table Text Block]

The following table summarizes the Company’s unvested stock option activity for the three months ended March 31, 2013:

	Shares		Weighted- Average Exercise Price (per Share)
	(Amounts in thousands)
Unvested at December 31, 2012	3,690		$	17.69
Granted	12		26.26
Vested	(6	)	17.95
Forfeited	(18	)	17.65
Unvested at March 31, 2013	3,678		$	17.72

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

The following table summarizes the Company’s unvested restricted stock unit activity for the three months ended March 31, 2013:

	Units		Weighted- Average Grant Date Fair Value (per Unit)
	(Amounts in thousands)
Unvested at December 31, 2012	1,446		$	18.61
Granted	4		26.26
Vested	(7	)	18.02
Forfeited	(9	)	18.50
Unvested at March 31, 2013	1,434		$	18.64