Financial Statements - Additional Information (Detail)	Sep. 30, 2013
Summary of Accounting and Financial Policies [Line Items]
Parent company percentage owned by affiliates	99.00%
Acofran [Member]
Summary of Accounting and Financial Policies [Line Items]
Ownership percentage by parent	50.00%
Ryerson China [Member]
Summary of Accounting and Financial Policies [Line Items]
Ownership percentage by parent	50.00%
Additional ownership interest through affiliates	50.00%