CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Thousands, $ in Thousands		3 Months Ended								12 Months Ended
		Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019		Dec. 31, 2018		Dec. 31, 2017
Total revenue		$ 247,748	$ 276,839	$ 306,170	$ 300,494	$ 313,133	$ 316,171	$ 305,747	$ 283,105	$ 1,131,251		$ 1,218,156		$ 1,010,466
Cost of goods and services										754,147		801,152		690,398
Gross profit		72,634	92,699	108,760	103,011	106,595	112,327	104,090	93,992	377,104		417,004		320,068
Selling, general and administrative expense										276,014		264,947		221,407
Interest expense, net										39,301		27,648		863
Other expense, net										2,603		3,056		9,443
Income before income taxes										59,186		121,353		88,355
Provision for (benefit from) income taxes										6,226		28,162		(22,164)
Net income		(1,574)	11,588	23,008	19,938	23,347	24,015	21,879	23,950	52,960		93,191		110,519
Net income attributable to noncontrolling interest										796		454		930
Net income attributable to Apergy		$ (1,823)	$ 11,394	$ 22,937	$ 19,656	$ 23,187	$ 23,961	$ 21,816	$ 23,773	$ 52,164		$ 92,737		$ 109,589
Earnings per share attributable to Apergy:
Basic (in dollars per share)		$ (0.02)	$ 0.15	$ 0.30	$ 0.25	$ 0.30	$ 0.31	$ 0.28	$ 0.31	$ 0.67	[1]	$ 1.20	[1]	$ 1.42	[1]
Diluted (in dollars per share)		$ (0.02)	$ 0.15	$ 0.30	$ 0.25	$ 0.30	$ 0.31	$ 0.28	$ 0.31	$ 0.67	[1]	$ 1.19	[1]	$ 1.41	[1]
Weighted-average shares outstanding:
Basic (in shares)	[1]									77,427		77,342		77,340
Diluted (in shares)	[1]									77,624		77,692		77,890
Product revenue
Revenue										$ 1,000,630		$ 1,090,218		$ 922,692
Other revenue
Revenue										$ 130,621		$ 127,938		$ 87,774

[1] See Note 4—Earnings Per Share.