Disclosure of Incentive Compensation Plan (Tables)

6 Months Ended

Jun. 30, 2011

Disclosure of Incentive Compensation plan (Tables) [Abstract]

Performance Based Units Earned Under Long Term Incentive Plans [Table Text Block]

	Long-Term Incentive Plan Years
	2007-2009			2008-2010
Performance stock units outstanding at January 1, 2010		559,951			290,860
Accrued dividend equivalents		—			3,138
Performance stock units settled		(559,951	)		—
Performance stock units outstanding at June 30, 2010		—			293,998
		2008-2010			2010-2012
Performance stock units outstanding at January 1, 2011		480,858			60,082
Accrued dividend equivalents		—			602
Performance stock units settled		(480,858	)		—
Performance stock units outstanding at June 30, 2011		—			60,684

Disclosure of Share-based Compensation Arrangements by Share-based Payment Award [Text Block]

	Long-Term Incentive Plan Years
	2009 - 2011			2010 - 2012			2011 - 2013
January 1, 2011
Outstanding		816,500			303,120			—
Exercisable		164,500			—			—
Granted					—			311,670
Cancelled		(2,000	)		(13,000	)		—
Exercised		(110,500	)		(10,034	)		—
June 30, 2011
Outstanding		704,000			280,086			311,670
Exercisable		410,000			91,008			—

Details Of Restricted Stock Unit Activity [Table Text Block]

	2010			2011
Restricted stock units outstanding at January 1		526,809			242,273
Restricted stock units granted		—			100,400
Accrued dividend equivalents		2,981			2,962
Restricted stock units settled		(250,021	)		(23,491	)
Restricted stock units cancelled		(4,149	)		(1,638	)
Restricted stock units outstanding at June 30		275,620			320,506

Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Text Block]

	Three months ended June 30				Six months ended June 30
	2010		2011		2010		2011
Stock options	$	396	$	727	$	617	$	1,220
Restricted stock units		477		316		644		598
Performance stock units		1,572		317		2,271		521
Total stock based compensation	$	2,445	$	1,360	$	3,532	$	2,339

Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions And Methodology [Table Text Block]

	2010			2011
Risk-free interest rate		2.8	%		2.7	%
Dividend yield		2.2	%		1.8	%
Expected volatility of the Company’s common stock		0.604			0.615
Expected life in years		6.0			6.0