Segment Information (Segment Reconciliation) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Segment Reporting Information [Line Items]
REVENUES	$ 221,675	$ 193,261	$ 176,549	$ 177,385	$ 181,581	$ 142,305	$ 148,353	$ 147,025	$ 768,870	$ 619,264	$ 589,592
Customer revenues	221,675	$ 193,261	$ 176,549	$ 177,385	181,581	$ 142,305	$ 148,353	$ 147,025	768,870	619,264	589,592
Depreciation and amortization expense									135,496	125,443	108,254
Net unallocated interest expense									(11,318)	(11,232)	(13,937)
Net gain (loss) on financial instruments									(18,107)	920	1,096
Pre-tax earnings from continuing operations									34,454	62,563	51,776
Assets	1,259,330				1,041,721				1,259,330	1,041,721	1,011,203
Customer Revenues [Member]
Segment Reporting Information [Line Items]
REVENUES									768,870	619,264	589,592
Customer revenues									768,870	619,264	589,592
CAM [Member]
Segment Reporting Information [Line Items]
REVENUES									195,092	177,789	166,303
Customer revenues									195,092	177,789	166,303
Depreciation and amortization expense									92,396	87,765	78,866
Segment earnings (loss)									68,608	57,457	53,159
Net unallocated interest expense									(10,600)	(9,400)	(11,800)
Assets	971,986				804,776				971,986	804,776	798,508
CAM [Member] | Customer Revenues [Member]
Segment Reporting Information [Line Items]
REVENUES									117,642	93,395	77,668
Customer revenues									117,642	93,395	77,668
ACMI Services [Member]
Segment Reporting Information [Line Items]
REVENUES									492,859	433,109	439,919
Customer revenues									492,859	433,109	439,919
Depreciation and amortization expense									41,487	37,526	29,929
Segment earnings (loss)									(32,125)	(2,654)	(12,081)
Assets	164,489				154,852				164,489	154,852	133,861
ACMI Services [Member] | Customer Revenues [Member]
Segment Reporting Information [Line Items]
REVENUES									492,859	431,989	439,919
Customer revenues									492,859	431,989	439,919
All other [Member]
Segment Reporting Information [Line Items]
REVENUES									262,539	161,995	142,294
Customer revenues									262,539	161,995	142,294
Depreciation and amortization expense									1,613	152	(541)
Segment earnings (loss)									16,623	8,561	11,363
Assets	$ 122,855				$ 82,093				122,855	82,093	78,834
All other [Member] | Customer Revenues [Member]
Segment Reporting Information [Line Items]
REVENUES									158,369	93,880	72,005
Customer revenues									158,369	93,880	72,005
Significant Reconciling Items [Member]
Segment Reporting Information [Line Items]
Net unallocated interest expense									(545)	(1,721)	(1,761)
Eliminate inter-segment revenues [Member]
Segment Reporting Information [Line Items]
REVENUES									(181,620)	(153,629)	(158,924)
Customer revenues									$ (181,620)	$ (153,629)	$ (158,924)