Segment Information (Segment Reconciliation) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Segment Reporting Information [Line Items]
Total revenues	$ 140,877	$ 153,826	$ 423,060	$ 452,886
Customer revenues	140,877	153,826	423,060	452,886
Depreciation and amortization expense	23,392	21,057	66,077	62,871
Net unallocated interest expense	(3,814)	(3,668)	(10,500)	(10,886)
Net gain (loss) on derivative instruments	(317)	294	425	956
Pre-tax earnings from continuing operations	12,496	18,959	37,173	47,873
Assets	1,066,131		1,066,131		1,035,611
CAM [Member]
Segment Reporting Information [Line Items]
Total revenues	40,089	39,155	118,420	115,073
Customer revenues	17,373	18,638	53,553	56,663
Depreciation and amortization expense	16,697	15,187	46,016	44,288
Segment earnings (loss)	15,893	17,334	49,980	50,819
Net unallocated interest expense	(3,300)	(3,100)	(9,200)	(9,100)
Assets	807,571		807,571		810,664
ACMI Services [Member]
Segment Reporting Information [Line Items]
Total revenues	109,429	122,526	327,349	357,110
Customer revenues	109,429	122,526	327,349	357,110
Depreciation and amortization expense	6,821	5,685	19,651	18,244
Segment earnings (loss)	(7,113)	(1,746)	(21,610)	(11,543)
Net unallocated interest expense	(100)	(200)	(400)	(700)
Assets	177,603		177,603		161,650
All other [Member]
Segment Reporting Information [Line Items]
Total revenues	30,037	26,773	83,242	81,876
Customer revenues	14,075	12,662	42,158	39,113
Depreciation and amortization expense	(126)	185	410	339
Segment earnings (loss)	4,400	3,373	9,188	8,602
Assets	80,957		80,957		63,297
Eliminate inter-segment revenues [Member]
Segment Reporting Information [Line Items]
Total revenues	(38,678)	(34,628)	(105,951)	(101,173)
Net unallocated interest expense [Member]
Segment Reporting Information [Line Items]
Net unallocated interest expense	$ (367)	$ (296)	$ (810)	$ (961)