CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
CURRENT ASSETS:
Cash and cash equivalents	$ 24,196	$ 21,150
Accounts receivable, less allowances for discounts and expected credit losses of $5,816 and $5,375 in 2023 and 2022, respectively	210,801	167,638
Inventories	522,039	528,715
Unreturned customer inventories	20,626	19,695
Prepaid expenses and other current assets	26,192	25,241
Total current assets	803,854	762,439
Property, plant and equipment, net of accumulated depreciation of $244,392 and $239,176 for 2023 and 2022, respectively	107,123	107,148
Operating lease right-of-use assets	74,291	49,838
Goodwill	132,289	132,087
Other intangibles, net	98,389	100,504
Deferred income taxes	33,893	33,658
Investments in unconsolidated affiliates	42,719	41,745
Other assets	27,462	27,510
Total assets	1,320,020	1,254,929
CURRENT LIABILITIES:
Current portion of revolving credit facility	52,600	50,000
Current portion of term loan and other debt	5,014	5,031
Accounts payable	94,372	89,247
Sundry payables and accrued expenses	42,041	49,990
Accrued customer returns	42,153	37,169
Accrued core liability	21,319	22,952
Accrued rebates	39,657	37,381
Payroll and commissions	24,268	31,361
Total current liabilities	321,424	323,131
Long-term debt	215,487	184,589
Noncurrent operating lease liabilities	65,319	40,709
Other accrued liabilities	24,298	22,157
Accrued asbestos liabilities	60,820	63,305
Total liabilities	687,348	633,891
Commitments and contingencies
Stockholders' equity:
Common stock - par value $2.00 per share: Authorized - 30,000,000 shares; issued 23,936,036 shares	47,872	47,872
Capital in excess of par value	106,675	105,615
Retained earnings	569,899	564,242
Accumulated other comprehensive income	(11,001)	(12,470)
Treasury stock - at cost (2,265,530 shares and 2,350,377 shares in 2023 and 2022, respectively)	(91,801)	(95,239)
Total SMP stockholders' equity	621,644	610,020
Noncontrolling interest	11,028	11,018
Total stockholders' equity	632,672	621,038
Total liabilities and stockholders' equity	$ 1,320,020	$ 1,254,929