Segment Information (Entity-Wide Disclosures) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Segment Reporting Information [Line Items]
Customer revenues	$ 154,552	$ 153,826	$ 153,554	$ 145,506	$ 166,465	$ 195,480	$ 193,061	$ 175,127	$ 607,438	$ 730,133	$ 667,382
All other [Member]
Segment Reporting Information [Line Items]
Customer revenues									55,117	57,391	45,890
Aircraft maintenance and part sales [Member] | All other [Member]
Segment Reporting Information [Line Items]
Customer revenues									21,669	25,845	15,963
Mail handling services [Member] | All other [Member]
Segment Reporting Information [Line Items]
Customer revenues									23,671	21,613	19,386
Facility and ground equipment maintenance [Member] | All other [Member]
Segment Reporting Information [Line Items]
Customer revenues									8,304	8,465	8,868
Other [Member] | All other [Member]
Segment Reporting Information [Line Items]
Customer revenues									$ 1,473	$ 1,468	$ 1,673