Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Assets
Cash	$ 1,167	$ 1,630
Accounts receivable, net of allowance for doubtful accounts of $2,038 in 2014 and $2,007 in 2013	101,294	87,650
Rental equipment, at cost:
Relocatable modular buildings	664,340	592,391
Electronic test equipment	261,995	267,772
Liquid and solid containment tanks and boxes	303,303	284,005
Rental equipment, gross	1,229,638	1,144,168
Less accumulated depreciation	(403,888)	(377,158)
Rental equipment, net	825,750	767,010
Property, plant and equipment, net	108,628	105,187
Prepaid expenses and other assets	41,424	27,772
Intangible assets, net	10,336	10,662
Goodwill	27,808	27,700
Total assets	1,116,407	1,027,611
Liabilities:
Notes payable	322,478	290,003
Accounts payable and accrued liabilities	71,357	63,318
Deferred income	29,139	24,003
Deferred income taxes, net	268,902	249,257
Total liabilities	691,876	626,581
Commitments and contingencies (Note 7)
Shareholders' equity:
Common stock, no par value-authorized-40,000 shares issued and outstanding-26,051 shares as of December 31, 2014 and 25,757 shares as of December 31, 2013	106,469	103,023
Retained earnings	318,164	298,038
Accumulated other comprehensive loss	(102)	(31)
Total shareholders' equity	424,531	401,030
Total liabilities and shareholders' equity	$ 1,116,407	$ 1,027,611