Comprehensive Income

9 Months Ended

Sep. 30, 2011

Comprehensive Income [Abstract]

Comprehensive Income

11. Comprehensive Income

The components of total comprehensive income are shown below:

	Three Months Ended Sept. 30,				Nine Months Ended Sept. 30,
(Thousands of Dollars)	2011		2010		2011		2010
Net income	$	19,973	$	17,624	$	43,094	$	33,847
Other comprehensive income:
After-tax net realized losses on derivative transactions reclassified into earnings		19		19		57		57
Comprehensive income	$	19,992	$	17,643	$	43,151	$	33,904