Earnings Per Share - Reconciliation of the weighted-average shares outstanding used in the calculation of basic and diluted EPS (Details) - USD ($) $ / shares in Units, 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
Earnings Per Share
Income from continuing operations	$ 10,479	$ 7,256	$ 23,373	$ 15,387	$ 19,222	$ 35,157	$ 46,400	$ 46,370	$ 56,495	$ 147,149	$ 136,101
Income from continuing operations attributable to noncontrolling interest	$ 5	$ 10	$ 11	$ 8	$ 4	$ 7	$ 44	$ 31	34	86
Income from continuing operations attributable to Advanced Energy Industries, Inc.									$ 56,461	$ 147,063	$ 136,101
Basic weighted-average common shares outstanding									38,281	39,081	39,754
Assumed exercise of dilutive stock options and restricted stock units									214	271	422
Diluted weighted-average common shares outstanding									38,495	39,352	40,176
Continuing Operations:
Basic earnings per share (in dollars per share)	$ 0.27	$ 0.19	$ 0.61	$ 0.40	$ 0.50	$ 0.90	$ 1.18	$ 1.17	$ 1.47	$ 3.76	$ 3.42
Diluted earnings per share (in dollars per share)	$ 0.27	$ 0.19	$ 0.61	$ 0.40	$ 0.50	$ 0.90	$ 1.17	$ 1.16	$ 1.47	$ 3.74	$ 3.39