OM GROUP INC

Q: Jun 30 2015

Q: Mar 31 2015

FY: Dec 31 2014

Q: Sep 30 2014

Q: Jun 30 2014

Q: Mar 31 2014

FY: Dec 31 2013

Q: Sep 30 2013

Q: Jun 30 2013

Q: Mar 31 2013

FY: Dec 31 2012

Q: Sep 30 2012

Q: Mar 31 2012

Q: Jun 30 2012

Q: Sep 30 2012

Q: Jun 30 2012

Q: Mar 31 2012

FY: Dec 31 2011

Q: Sep 30 2011

Q: Jun 30 2011

5.07,9.01

8.01,9.01

5.02,5.07

1.01,5.03,8.01,9.01

2.02,9.01

1.01,8.01,9.01

2.02,9.01

2.02

2.02,9.01

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers: Compensatory Arrangements of Certain Officers

5.02

2.02,9.01

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers: Compensatory Arrangements of Certain Officers

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers: Compensatory Arrangements of Certain Officers

Results of Operations and Financial Condition

5.02

2.02,9.01

5.02

2.02,9.01

1.01,1.02,2.03,8.01,9.01

Post Effective Amendment to S-8

Post Effective Amendment to S-8

Post Effective Amendment to S-8

Post Effective Amendment to S-8

Post Effective Amendment to S-8

Post Effective Amendment to S-8

Certification of termination of registration of a class of securities (Section 12(b))

Notification of removal from listing and/or registration on a national securities exchange

Registration statement under Securities Act of 1933 to be offered to employees pursuant to certain plans

Post Effective Amendment to S-8

Registration statement under Securities Act of 1933 to be offered to employees pursuant to certain plans

Registration statement under Securities Act of 1933 to be offered to employees pursuant to certain plans

Prospectus Supplement for Primary Offering

Registration statement under Securities Act of 1933 (amendment)

Registration statement under Securities Act of 1933

Prospectus Supplement with Pricing Information

Amended Initial Registration Statement

No description available

Registration (IPO) statement under Securities Act of 1933

Registration statement under Securities Act of 1933 to be offered to employees pursuant to certain plans

No description available

No description available

Additional Information for Proxy Statement/ Votes

Additional Information for Proxy Statement/ Votes

Additional Information for Proxy Statement/ Votes

Additional Information for Proxy Statement/ Votes

Definitive Proxy Statement

Additional proxy soliciting materials filed by a non-management party

Additional proxy soliciting materials filed by a non-management party

Additional Information for Proxy Statement/ Votes

Definitive Proxy Statement

Definitive Proxy Statement

Additional Information for Proxy Statement/ Votes

Definitive Proxy Statement

Shareholder Letter

Additional Information for Proxy Statement/ Votes

Definitive Proxy Statement

Definitive Proxy Statement

Definitive Proxy Statement

Definitive Proxy Statement

DIMENSIONAL FUND ADVISORS LP

Capital Research Global Investors

none

Mullin Patrick S.

GINGO JOSEPH M

SPIZZO ALLEN A

Johnson Michael V.

SCAMINACE JOSEPH

Christenson Carl R

Griffith Greg J

MCFARLAND JOHN A

Hix Christopher M

Knowles David B

PLOURDE KATHARINE

BETZ HANS GEORG DR

SACHS VALERIE GENTILE

SCAMINACE JOSEPH

Mullin Patrick S.

GINGO JOSEPH M

BLACKBURN RICHARD W

Specialized Disclosure Report

Annual Report Scanned (Paper)

Letter from the SEC

Letter from the SEC

Correspondence with the SEC

Letter from the SEC

Specialized Disclosure Report

Annual Report Scanned (Paper)

Annual Report Scanned (Paper)

Letter from the SEC

Correspondence with the SEC

Letter from the SEC

Annual Report Scanned (Paper)

Correspondence with the SEC

Letter from the SEC

Correspondence with the SEC

Letter from the SEC

Annual Report Scanned (Paper)

Letter from the SEC

Correspondence with the SEC