Quarterly Results of Operations (Tables)

12 Months Ended

Dec. 31, 2013

Quarterly Financial Information Disclosure [Abstract]

Schedule of Quarterly Financial Information [Table Text Block]

A summary of quarterly results of operations for the years ended December 31, 2013 and 2012 follows. Certain amounts have been reclassified to conform to the current presentation of discontinued operations (in thousands, except per share amounts).

	QUARTER ENDED
	DEC. 31,	SEPT. 30,	JUNE 30,	MAR. 31,	DEC. 31,	SEPT. 30,	JUNE 30,	MAR. 31,
	2013	2013	2013	2013	2012	2012	2012	2012
Operating revenue	$192,427	$155,349	$151,026	$147,128	$144,431	$140,515	$137,987	$137,346
Income from continuing operations	19,911	23,406	29,611	24,827	23,776	22,358	24,725	25,888
Discontinued operations	51,832	6,544	13,633	49,830	16,795	7,539	12,956	13,714
Net income	71,743	29,950	43,244	74,657	40,571	29,897	37,681	39,602
Income per common share - basic (1)	0.48	0.21	0.33	0.60	0.33	0.24	0.29	0.32
Income per common share - diluted (1)	0.48	0.21	0.33	0.60	0.32	0.24	0.29	0.32

(1) The sum of quarterly financial data may vary from the annual data due to rounding.