Net Income Attributable To IPG Photonics Corporation Per Share (Computation of Diluted Net Income) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Earnings Per Share [Abstract]
Net income attributable to IPG Photonics Corporation	$ 57,253	$ 100,517	$ 184,684	$ 328,468
Net income attributable to common stockholders	$ 57,253	$ 100,517	$ 184,684	$ 328,468
Weighted average shares (in shares)	52,928	53,571	53,073	53,677
Dilutive effect of common stock equivalents (in shares)	694	1,125	791	1,318
Diluted weighted average common shares (in shares)	53,622	54,696	53,864	54,995
Basic net income attributable to IPG Photonics Corporation per share (in dollars per share)	$ 1.08	$ 1.88	$ 3.48	$ 6.12
Basic net income attributable to common stockholders (in dollars per share)	1.08	1.88	3.48	6.12
Diluted net income attributable to IPG Photonics Corporation per share (in dollars per share)	1.07	1.84	3.43	5.97
Diluted net income attributable to common stockholders (in dollars per share)	$ 1.07	$ 1.84	$ 3.43	$ 5.97