Basic and Diluted Per Share (Tables)

9 Months Ended

Sep. 30, 2012

Basic and Diluted Per Share Data [Abstract]

Schedule of Earnings Per Share Reconciliation [Table Text Block]

The reconciliation of basic net income per common share to diluted net income per common share is shown in the following table for the three and nine-month periods ended September 30, 2012 and 2011:

	September 30, 2012					September 30, 2011
	Net Income		Shares	EPS		Net Income		Shares	EPS
Three Months
Basic net income	$	40,633	48,416,895	$	0.84	$	56,997	48,405,860	$	1.18
Effect of dilutive securities:
Restricted stock	—		18,746	—		—		11,706	—
Performance units	—		44,766	—		—		60,626	—
Diluted net income	$	40,633	48,480,407	$	0.84	$	56,997	48,478,192	$	1.18
Nine Months
Basic net income	$	161,835	48,411,854	$	3.34	$	202,426	48,400,778	$	4.18
Effect of dilutive securities:
Restricted stock	—		17,177	—		—		10,730	—
Performance units	—		51,572	—		—		67,425	—
Diluted net income	$	161,835	48,480,603	$	3.34	$	202,426	48,478,933	$	4.18