Condensed Consolidating Balance Sheets (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016
ASSETS
Cash and cash equivalents	$ 7,763	$ 13,451	$ 7,609	$ 4,137
Receivables, net	105,828	111,562
Inventories	16,811	15,671
Rental fleet, net	999,215	989,154
Property, plant and equipment, net	158,278	157,304
Other assets	13,370	15,334
Intangibles, net	60,442	62,024
Goodwill	711,063	708,907
Total assets	2,072,770	2,073,407
Liabilities:
Accounts payable	29,187	26,955
Accrued liabilities	66,337	78,084
Lines of credit	621,843	634,285
Obligations under capital leases	53,697	52,791
Senior notes, net	246,010	245,850
Deferred income taxes	178,361	173,754
Total liabilities	1,195,435	1,211,719
Commitments and contingencies
Stockholders' equity:
Common stock	499	497
Additional paid-in capital	609,120	605,369
Retained earnings	467,123	463,322
Accumulated other comprehensive loss	(51,708)	(60,334)
Treasury stock, at cost	(147,699)	(147,166)
Total stockholders' equity	877,335	861,688
Total liabilities and stockholders' equity	2,072,770	2,073,407
Eliminations
ASSETS
Intercompany receivables	(181,230)	(150,661)
Total assets	(181,230)	(150,661)
Liabilities:
Intercompany payables	(33,231)	(2,662)
Total liabilities	(33,231)	(2,662)
Commitments and contingencies
Stockholders' equity:
Additional paid-in capital	(147,999)	(147,999)
Total stockholders' equity	(147,999)	(147,999)
Total liabilities and stockholders' equity	(181,230)	(150,661)
Guarantors
ASSETS
Cash and cash equivalents	2,197	803	1,177	1,260
Receivables, net	87,360	91,624
Inventories	14,025	13,471
Rental fleet, net	826,422	823,997
Property, plant and equipment, net	133,002	133,919
Other assets	11,655	13,324
Intangibles, net	59,830	61,360
Goodwill	645,126	645,126
Intercompany receivables	146,517	145,855
Total assets	1,926,134	1,929,479
Liabilities:
Accounts payable	20,838	21,004
Accrued liabilities	58,005	71,298
Lines of credit	599,319	634,285
Obligations under capital leases	53,557	52,648
Senior notes, net	246,010	245,850
Deferred income taxes	157,059	153,345
Intercompany payables	29,470	1,437
Total liabilities	1,164,258	1,179,867
Commitments and contingencies
Stockholders' equity:
Common stock	499	497
Additional paid-in capital	609,120	605,369
Retained earnings	299,956	290,912
Treasury stock, at cost	(147,699)	(147,166)
Total stockholders' equity	761,876	749,612
Total liabilities and stockholders' equity	1,926,134	1,929,479
Non-Guarantors
ASSETS
Cash and cash equivalents	5,566	12,648	$ 6,432	$ 2,877
Receivables, net	18,468	19,938
Inventories	2,786	2,200
Rental fleet, net	172,793	165,157
Property, plant and equipment, net	25,276	23,385
Other assets	1,715	2,010
Intangibles, net	612	664
Goodwill	65,937	63,781
Intercompany receivables	34,713	4,806
Total assets	327,866	294,589
Liabilities:
Accounts payable	8,349	5,951
Accrued liabilities	8,332	6,786
Lines of credit	22,524
Obligations under capital leases	140	143
Deferred income taxes	21,302	20,409
Intercompany payables	3,761	1,225
Total liabilities	64,408	34,514
Commitments and contingencies
Stockholders' equity:
Additional paid-in capital	147,999	147,999
Retained earnings	167,167	172,410
Accumulated other comprehensive loss	(51,708)	(60,334)
Total stockholders' equity	263,458	260,075
Total liabilities and stockholders' equity	$ 327,866	$ 294,589