Segment Information (Segment Reconciliation) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Segment Reporting Information [Line Items]
Total revenues	$ 143,279	$ 145,506
Customer revenues	143,279	145,506
Depreciation and amortization expense	20,920	20,300
Net unallocated interest expense	(3,132)	(3,547)
Net gain on derivative instruments	290	460
Pre-tax earnings from continuing operations	13,592	10,743
Assets	1,089,154		1,035,611
CAM [Member]
Segment Reporting Information [Line Items]
Total revenues	38,969	37,851
Customer revenues	18,336	19,389
Depreciation and amortization expense	14,516	14,421
Segment earnings (loss)	16,873	16,818
Net unallocated interest expense	(2,600)	(3,000)
Assets	841,619		810,664
ACMI Services [Member]
Segment Reporting Information [Line Items]
Total revenues	113,051	113,195
Customer revenues	111,315	113,195
Depreciation and amortization expense	6,138	5,804
Segment earnings (loss)	(5,404)	(8,215)
Net unallocated interest expense	(200)	(200)
Assets	161,207		161,650
All other [Member]
Segment Reporting Information [Line Items]
Total revenues	26,254	28,421
Customer revenues	13,628	12,922
Depreciation and amortization expense	266	75
Segment earnings (loss)	2,181	2,001
Assets	86,328		63,297
Eliminate inter-segment revenues [Member]
Segment Reporting Information [Line Items]
Total revenues	(34,995)	(33,961)
Net unallocated interest expense [Member]
Segment Reporting Information [Line Items]
Net unallocated interest expense	$ (348)	$ (321)