SCHEDULE I - Parent Company Information - Condensed Balance Sheets (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
ASSETS
Cash and cash equivalents	$ 13,493,000	$ 12,801,000	$ 5,379,000	$ 6,440,000
Equipment held for operating lease, less accumulated depreciation	1,066,448,000	1,033,022,000	961,459,000
Equipment held for sale	18,114,000	32,491,000
Operating lease related receivable, net of allowances	8,912,000	13,286,000
Investments	41,590,000	23,485,000
Deferred income taxes	41,030,000	40,739,000
Property, equipment & furnishings, less accumulated depreciation	17,955,000	4,950,000
Intangible assets, net	1,164,000	1,396,000
Equipment purchase deposits		1,369,000
Other assets, net	24,099,000	22,355,000
Total assets	1,261,626,000	1,199,229,000
Liabilities:
Accounts payable and accrued expenses	21,614,000	16,283,000
Deferred income taxes	90,510,000	86,685,000
Notes payable	840,956,000	787,614,000
Maintenance reserves	66,474,000	77,335,000
Security deposits	20,869,000	15,158,000
Unearned lease revenue	4,342,000	3,549,000
Total liabilities	1,044,765,000	986,624,000
Shareholders' equity:
Preferred stock ($0.01 par value, 5,000,000 shares authorized; 0 shares issued and outstanding at December 31, 2014 and 2013)
Common stock ($0.01 par value, 20,000,000 shares authorized; 8,346,304 and 8,399,739 shares issued and outstanding at December 31, 2014 and 2013, respectively)	83,000	84,000
Paid-in capital in excess of par	42,076,000	44,741,000
Retained earnings	174,702,000	167,455,000
Accumulated other comprehensive loss, net of income (loss) tax expense (benefit)		325,000
Total shareholders' equity	216,861,000	212,605,000	199,163,000	236,271,000
Total liabilities and shareholders' equity	1,261,626,000	1,199,229,000
Parent Company
ASSETS
Cash and cash equivalents	2,411,000	1,520,000	4,142,000	6,429,000
Equipment held for operating lease, less accumulated depreciation	628,341,000	464,912,000
Equipment held for sale	15,768,000	26,382,000
Operating lease related receivable, net of allowances	3,379,000	1,911,000
Due from affiliate	19,044,000	1,393,000
Investments	41,590,000	23,485,000
Investment in subsidiaries	6,054,000	97,869,000
Deferred income taxes	14,906,000
Property, equipment & furnishings, less accumulated depreciation	17,867,000	4,868,000
Intangible assets, net	271,000	271,000
Equipment purchase deposits		1,369,000
Other assets, net	13,528,000	9,774,000
Total assets	763,159,000	633,754,000
Liabilities:
Accounts payable and accrued expenses	10,820,000	8,813,000
Deferred income taxes	26,132,000	6,993,000
Notes payable	457,364,000	378,828,000
Maintenance reserves	32,845,000	15,282,000
Security deposits	16,864,000	10,008,000
Unearned lease revenue	2,273,000	1,225,000
Total liabilities	546,298,000	421,149,000
Shareholders' equity:
Common stock ($0.01 par value, 20,000,000 shares authorized; 8,346,304 and 8,399,739 shares issued and outstanding at December 31, 2014 and 2013, respectively)	83,000	84,000
Paid-in capital in excess of par	42,076,000	44,741,000
Retained earnings	174,702,000	167,455,000
Accumulated other comprehensive loss, net of income (loss) tax expense (benefit)		325,000
Total shareholders' equity	216,861,000	212,605,000
Total liabilities and shareholders' equity	$ 763,159,000	$ 633,754,000