Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Current assets
Allowances for doubtful accounts	$ 35.7	$ 37.5
Accumulated depreciation and amortization	$ 548.1	$ 536.1
Diebold Nixdorf, Incorporated shareholders' equity
Preferred Stock, No Par Value	$ 0	$ 0
Preferred shares, shares authorized	1,000,000	1,000,000
Preferred shares, shares issued	0	0
Common shares, par value	$ 1.25	$ 1.25
Common shares, shares authorized	125,000,000	125,000,000
Common shares, shares issued	94,593,267	93,534,866
Common shares, shares outstanding	78,348,114	77,678,984
Treasury shares, at cost, shares	16,245,153	15,855,882