Quarterly Results Of Operations (Tables)

12 Months Ended

Aug. 31, 2012

Quarterly Results Of Operations [Abstract]

Schedule of Quarterly Results

	First		Second		Third		Fourth
$ in thousands, except per share amounts	Quarter		Quarter		Quarter		Quarter
Year ended August 31, 2012
Operating revenues	$	119,205	$	132,134	$	172,099	$	127,817
Cost of operating revenues		88,957		95,640		123,071		95,069
Earnings before income taxes		4,441		19,427		28,587		12,653
Net earnings		2,921		12,774		18,823		8,759
Diluted net earnings per share(1)	$	0.23	$	1.00	$	1.47	$	0.68
Market price (NYSE)
High	$	63.40	$	67.27	$	70.13	$	74.62
Low	$	46.03	$	49.17	$	52.98	$	52.68
Year ended August 31, 2011
Operating revenues	$	89,166	$	120,168	$	153,446	$	116,110
Cost of operating revenues		64,943		86,159		111,947		86,056
Earnings before income taxes		6,577		17,001		23,159		9,777
Net earnings		4,286		11,325		15,289		5,902
Diluted net earnings per share(1)	$	0.34	$	0.89	$	1.20	$	0.46
Market price (NYSE)
High	$	66.48	$	79.56	$	85.87	$	73.03
Low	$	37.22	$	58.00	$	61.85	$	47.68
(1) The quarterly diluted net earnings per share is calculated based on the weighted average shares outstanding assuming dilution for the quarter. There may be rounding differences between the sum of the quarterly diluted net earnings per share amounts and the year-to-date diluted net earnings per share.