CONSOLIDATED STATEMENTS OF OPERATIONS (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended							9 Months Ended
	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Sep. 30, 2013	Sep. 30, 2012
CONSOLIDATED STATEMENTS OF OPERATIONS
OPERATING REVENUES	$ 623,414				$ 577,546			$ 1,720,999	$ 1,528,956
OPERATING EXPENSES AND COSTS	602,912				565,313			1,715,431	1,532,509
OPERATING INCOME (LOSS)	20,502				12,233			5,568	(3,553)
OTHER INCOME (EXPENSE)
Interest and dividend income	167				155			499	623
Interest expense and other related financing costs	(993)				(1,609)			(3,279)	(3,863)
Other, net	1,328				997			2,778	2,117
Total other income (expense)	502				(457)			(2)	(1,123)
INCOME (LOSS) BEFORE INCOME TAXES	21,004				11,776			5,566	(4,676)
INCOME TAX PROVISION (BENEFIT)	7,022				5,258			101	(4,873)
NET INCOME	$ 13,982				$ 6,518			$ 5,465	$ 197
EARNINGS PER COMMON SHARE
Basic (in dollars per share)	$ 0.52				$ 0.24			$ 0.20	$ 0.00
Diluted (in dollars per share)	$ 0.52				$ 0.24			$ 0.20	$ 0.00
AVERAGE COMMON SHARES OUTSTANDING
Basic (in shares)	25,736,810				25,613,315			25,690,184	25,535,969
Diluted (in shares)	25,736,810				25,613,315			25,690,184	25,535,969
CASH DIVIDENDS DECLARED PER COMMON SHARE (in dollars per share)	$ 0.03	$ 0.03	$ 0.03	$ 0.03	$ 0.03	$ 0.03	$ 0.03	$ 0.09	$ 0.09