Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash Flows from Operating Activities:
Net income	$ 79,406,000	$ 153,920,000	$ 38,251,000
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	81,975,000	78,416,000	81,179,000
Impairment of rental assets	39,000	1,639,000	0
Provision for doubtful accounts	581,000	1,480,000	1,892,000
Share-based compensation	4,111,000	3,198,000	3,091,000
Gain on sale of used rental equipment	(19,559,000)	(17,733,000)	(13,739,000)
Foreign currency exchanges (gain) loss	489,000	(334,000)	121,000
Amortization of debt issuance costs	20,000	50,000	51,000
Change in:
Accounts receivable	(15,725,000)	(10,475,000)	(3,752,000)
Income taxes receivable			11,000,000
Prepaid expenses and other assets	(9,351,000)	3,124,000	3,219,000
Accounts payable and accrued liabilities	(1,612,000)	4,015,000	10,426,000
Deferred income	10,258,000	1,720,000	1,211,000
Deferred income taxes	12,035,000	(96,631,000)	7,745,000
Net cash provided by operating activities	142,667,000	122,389,000	140,695,000
Cash Flows from Investing Activities:
Purchases of rental equipment	(123,071,000)	(94,579,000)	(79,038,000)
Purchases of property, plant and equipment	(15,664,000)	(14,617,000)	(10,548,000)
Cash paid for acquisition of business assets	(7,543,000)
Proceeds from sales of used rental equipment	41,786,000	38,344,000	29,406,000
Net cash used in investing activities	(104,492,000)	(70,852,000)	(60,180,000)
Cash Flows from Financing Activities:
Net borrowings (repayments) under bank lines of credit	15,130,000	(2,902,000)	(35,066,000)
Principal payments on Series A senior notes	(20,000,000)	(20,000,000)	(20,000,000)
Proceeds from the exercise of stock options			37,000
Taxes paid related to net share settlement of stock awards	(3,257,000)	(2,072,000)	(1,287,000)
Payment of dividends	(30,939,000)	(24,876,000)	(24,448,000)
Net cash used in financing activities	(39,066,000)	(49,850,000)	(80,764,000)
Effect of foreign currency exchange rate changes on cash	(102,000)	(38,000)	(2,000)
Net increase (decrease) in cash	(993,000)	1,649,000	(251,000)
Cash balance, beginning of period	2,501,000	852,000	1,103,000
Cash balance, end of period	1,508,000	2,501,000	852,000
Supplemental Disclosure of Cash Flow Information:
Interest paid, during the period	12,598,000	11,825,000	12,436,000
Net income taxes paid, during the period	18,157,000	29,504,000	15,555,000
Dividends accrued during the period, not yet paid	8,388,000	6,260,000	6,147,000
Rental equipment acquisitions, not yet paid	$ 9,695,000	$ 6,405,000	$ 2,876,000