Quarterly Results of Operations (Tables)

12 Months Ended

Dec. 31, 2014

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, 2014 and 2013 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,
	2014			2014		2014		2014		2013		2013		2013		2013
Operating revenue	$	203,685		$	198,356	$	192,960	$	197,630	$	192,427	$	155,349	$	151,026	$	147,128
Income from continuing operations	84,193		(2)	35,318		29,811		26,260		19,911		23,406		29,611		24,827
Discontinued operations	306			133		296		47,846		51,832		6,544		13,633		49,830
Net income	84,499			35,451		30,107		74,106		71,743		29,950		43,244		74,657
Income per common share - basic (1)	0.56			0.23		0.20		0.49		0.48		0.21		0.33		0.60
Income per common share - diluted (1)	0.55			0.23		0.20		0.49		0.48		0.21		0.33		0.60

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

(2) Includes gain on sale of $43.2 million.