Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Consolidated Balance Sheets
Leasing equipment, accumulated depreciation and allowances (in dollars)	$ 799,022	$ 766,898
Net investment in finance leases, allowances (in dollars)	823	897
Accounts receivable, allowances (in dollars)	$ 676	$ 692
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized	500,000	500,000
Preferred stock, shares issued	0	0
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	36,856,307	36,697,366
Treasury stock, shares	3,011,843	3,011,843