CONSOLIDATED STATEMENTS OF OPERATIONS (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended					6 Months Ended
	Jun. 30, 2013	Mar. 31, 2013	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Jun. 30, 2013	Jun. 30, 2012
CONSOLIDATED STATEMENTS OF OPERATIONS
OPERATING REVENUES	$ 576,899			$ 510,543		$ 1,097,586	$ 951,410
OPERATING EXPENSES AND COSTS	568,482			503,342		1,112,520	967,196
OPERATING INCOME (LOSS)	8,417			7,201		(14,934)	(15,786)
OTHER INCOME (EXPENSE)
Interest and dividend income	161			215		332	469
Interest expense and other related financing costs	(1,079)			(1,112)		(2,286)	(2,255)
Other, net	366			(220)		1,450	1,120
TOTAL OTHER INCOME (EXPENSE)	(552)			(1,117)		(504)	(666)
INCOME (LOSS) BEFORE INCOME TAXES	7,865			6,084		(15,438)	(16,452)
INCOME TAX PROVISION (BENEFIT)	2,987			(5,757)		(6,921)	(10,131)
NET INCOME (LOSS)	$ 4,878			$ 11,841		$ (8,517)	$ (6,321)
EARNINGS (LOSS) PER COMMON SHARE
Basic (in dollars per share)	$ 0.18			$ 0.44		$ (0.33)	$ (0.25)
Diluted (in dollars per share)	$ 0.18			$ 0.44		$ (0.33)	$ (0.25)
AVERAGE COMMON SHARES OUTSTANDING
Basic (in shares)	25,694,327			25,544,455		25,666,484	25,496,871
Diluted (in shares)	25,694,327			25,544,455		25,666,484	25,496,871
CASH DIVIDENDS DECLARED PER COMMON SHARE (in dollars per share)	$ 0.03	$ 0.03	$ 0.03	$ 0.03	$ 0.03	$ 0.06	$ 0.06