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
	Mar. 31, 2018	Mar. 31, 2017
Earnings Per Share [Abstract]
Income from continuing operations attributable to Advanced Energy Industries, Inc.	$ 46,370	$ 35,441
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest	31	0
Income from continuing operations attributable to noncontrolling interest	31	0
Income from continuing operations, net of income taxes	46,339	35,441
Net Income (Loss) Attributable to Parent	$ 46,479	$ 37,535
Basic weighted-average common shares outstanding	39,619	39,738
Assumed exercise of dilutive stock options and restricted stock units	376	441
Diluted weighted-average common shares outstanding	39,995	40,179
Income from Continuing Operations:
Income (Loss) from Continuing Operations, Per Basic Share	$ 1.17	$ 0.89
Income (Loss) from Continuing Operations, Per Diluted Share	$ 1.16	$ 0.88