CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Current assets
Accounts receivable, allowance for doubtful accounts	$ 3,626	$ 2,042
Rental equipment net of accumulated depreciation	1,889,266	1,816,794
Rental equipment, accumulated depreciation	598,545	557,559
Net investment in direct finance leases	472,790	473,792
Intangible assets, accumulated amortization	6,605	5,397
Current liabilities
Current portion of debt	309,500	311,381
Debt	$ 1,819,649	$ 1,847,633
Stockholders' equity
Preferred stock, par value	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	10,000,000	10,000,000
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	84,000,000	84,000,000
Common stock, shares issued	17,425,754	18,764,459
Common stock, shares outstanding	17,425,754	18,764,459
Variable Interest Entity, Primary Beneficiary [Member]
Current assets
Cash	$ 26,772	$ 25,211
Rental equipment net of accumulated depreciation	108,323	71,958
Net investment in direct finance leases	6,101	13,862
Current liabilities
Current portion of debt	28,650	41,066
Debt	$ 108,487	$ 67,615
Series A Fixed-to-Floating Rate Cumulative Redeemable Perpetual Preferred Stock [Member]
Stockholders' equity
Preferred stock, dividend rate	8.50%	8.50%
Preferred stock, shares issued	2,199,610	2,199,610
Preferred stock, shares outstanding	2,199,610	2,199,610
Series B Fixed-to-Floating Rate Cumulative Redeemable Perpetual Preferred Stock [Member]
Stockholders' equity
Preferred stock, dividend rate	8.50%	8.50%
Preferred stock, shares issued	1,955,000	1,955,000
Preferred stock, shares outstanding	1,955,000	1,955,000