QUARTERLY FINANCIAL DATA (UNAUDITED) (Tables)

12 Months Ended

Dec. 31, 2015

QUARTERLY FINANCIAL DATA (UNAUDITED)

Schedule of Quarterly Financial Information

		First		Second		Third		Fourth
Statement of Operations Data (thousands):		Quarter		Quarter		Quarter		Quarter		Total
2015
Operating revenues	$	328,391	$	305,913	$	388,102	$	313,042	$	1,335,448
Operating margins		49,384		38,550		81,412		8,623		177,969
Net margins attributable to the Association		20,126		6,284		48,302		(21,299)		53,413
2014
Operating revenues	$	349,198	$	327,288	$	396,479	$	322,126	$	1,395,091
Operating margins		53,652		34,098		69,603		24,524		181,877
Net margins attributable to the Association		24,511		3,373		40,451		(4,099)		64,236