SCHEDULE I - Parent Company Information - Condensed Balance Sheets (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
ASSETS
Cash and cash equivalents	$ 7,052	$ 10,076
Equipment held for operating lease, less accumulated depreciation	1,342,571	1,136,603
Equipment held for sale	34,172	30,710
Maintenance Rights	14,763	17,670
Operating lease related receivable, net of allowances	18,848	16,484
Spare parts inventory	16,379	25,443
Investments	50,641	45,406
Property, equipment & furnishings, less accumulated depreciation	26,074	16,802
Intangible assets, net	1,727	2,182
Other assets, net	50,932	14,213
Total assets	1,603,431	1,337,887	$ 1,294,285
Liabilities:
Accounts payable and accrued expenses	22,072	17,792
Deferred income taxes	113,910	147,405
Debt obligations	1,085,405	900,255
Maintenance reserves	75,889	71,602
Security deposits	25,302	21,417
Unearned lease revenue	8,102	5,823
Total liabilities	1,295,050	1,121,867
Redeemable preferred stock ($0.01 par value, 2,500 shares authorized; 2,500 and 1,000 shares issued and outstanding at December 31, 2017 and 2016, respectively)	49,471	19,760
Shareholders' equity:
Common stock ($0.01 par value, 20,000 shares authorized; 6,419 and 6,402 shares issued and outstanding at December 31, 2017 and 2016, respectively)	64	64
Paid-in capital in excess of par	2,319	2,512
Retained earnings	256,301	194,729
Accumulated other comprehensive loss, net of income tax benefit	226	(1,045)
Total shareholders' equity	258,910	196,260	209,223	$ 216,648
Total liabilities, redeemable preferred stock and shareholders' equity	1,603,431	1,337,887
Parent Company
ASSETS
Cash and cash equivalents	2,860	4,574	$ 2,894	$ 2,411
Equipment held for operating lease, less accumulated depreciation	662,162	811,091
Equipment held for sale	3,296	16,468
Maintenance Rights	34,084	22,446
Operating lease related receivable, net of allowances	7,980	7,853
Spare parts inventory	11,643	17,554
Due from affiliate	18,439	24,723
Investments	50,641	45,406
Investment in subsidiaries	50,047	(2,879)
Property, equipment & furnishings, less accumulated depreciation	15,238	16,096
Intangible assets, net	271	1,021
Prepaid deposits	36,455	4,399
Other assets, net	8,385	7,890
Total assets	901,501	976,642
Liabilities:
Accounts payable and accrued expenses	15,686	13,428
Due to affiliates, net	2,300
Deferred income taxes	7,456	43,265
Debt obligations	508,350	626,876
Maintenance reserves	36,809	54,655
Security deposits	17,795	18,555
Unearned lease revenue	4,724	3,843
Total liabilities	593,120	760,622
Redeemable preferred stock ($0.01 par value, 2,500 shares authorized; 2,500 and 1,000 shares issued and outstanding at December 31, 2017 and 2016, respectively)	49,471	19,760
Shareholders' equity:
Common stock ($0.01 par value, 20,000 shares authorized; 6,419 and 6,402 shares issued and outstanding at December 31, 2017 and 2016, respectively)	64	64
Paid-in capital in excess of par	2,319	2,512
Retained earnings	256,301	194,729
Accumulated other comprehensive loss, net of income tax benefit	226	(1,045)
Total shareholders' equity	258,910	196,260
Total liabilities, redeemable preferred stock and shareholders' equity	$ 901,501	$ 976,642