Debt	12 Months Ended
Dec. 31, 2016
Short-term Debt [Abstract]
Debt	2015 Credit Agreement On October 30, 2015, the Company and certain domestic subsidiaries (collectively with the Company, the “US Borrowers”), certain Canadian subsidiaries of the Company (collectively, the “Canadian Borrowers”), and certain UK subsidiaries of the Company (collectively, the “UK Borrowers”), collectively (the "Borrowers") entered into an agreement for a secured lending facility (the “2015 Credit Agreement”) with Bank of America, N.A. and other lenders. The 2015 Credit Agreement established a $150.0 million revolving line of credit facility which also includes an option to expand the facility by up to $75.0 million subject to agreement by the lenders, with a five-year term ending on October 30, 2020. In connection with the sale of Anders, the Company executed an amendment to the 2015 Credit Agreement to eliminate the UK Borrowers, release all liens and security interests on the UK collateral and allocate the available UK borrowings to the U.S. Borrowers. As of December 31, 2016, the facility is comprised of two subfacilities with $135.0 million available to the US Borrowers and $15.0 million available to the Canadian Borrowers. It also includes a $25.0 million sublimit for swingline loans and a $15.0 million sublimit for letters of credit. Availability under the 2015 Credit Agreement is tied to a borrowing base, measured by 85% of eligible billed accounts receivable, plus 80% of eligible unbilled accounts receivable, less customary reserve amounts; provided however that the portion of the borrowing base consisting of 80% of the eligible unbilled accounts receivable may not exceed 30% of the sum of (i) 85% of the eligible billed accounts receivable, plus (ii) 80% of the eligible unbilled accounts receivable. Borrowings under the 2015 Credit Agreement may be used by the Company and the other Borrowers for general business purposes including capital expenditures and permitted acquisitions and investments. Accounts receivable, used in the determination of the borrowing base, are subject to lender discretion and, in certain circumstances, the lender may use cash balances in a dominion account established with the administrative agent to repay outstanding balances. As a result, amounts borrowed under the 2015 Credit Agreement are presented as current in the consolidated balance sheets. The Borrowers’ obligations under the 2015 Credit Agreement are secured by a first lien security interest in all of the Borrowers’ personal property (subject to customary exceptions), including, among other things, accounts receivable, equity interests, deposit accounts, intellectual property, and leased properties where books and records are kept. Interest on borrowings under the 2015 Credit Agreement is based on either (i) LIBOR plus an applicable margin (tied to the Borrowers’ excess availability under the facility) of 1.25% to 1.75% or (ii) the Federal Funds Rate/Bank’s Prime Rate plus an applicable margin of 0.25% to 0.75%, as selected by the applicable Borrower with respect to each borrowing. There are customary fees associated with the facility including an unused commitment fee of 0.25% per annum on the daily amount of unused commitments. The 2015 Credit Agreement contains customary affirmative covenants, including with regard to financial reporting, and customary restrictive covenants. The 2015 Credit Agreement also contains a financial covenant which requires the Company’s fixed charge coverage ratio to exceed 1.0 to 1.0 if excess liquidity drops below an agreed threshold. The preceding financial covenant terms are further defined in the 2015 Credit Agreement. The Company was in compliance with all covenants under the 2015 Credit Agreement as of December 31, 2016 and December 31, 2015. As of December 31, 2016, the Company had no outstanding borrowings, letters of credit outstanding of $3.3 million and $122.3 million available to borrow under the 2015 Credit Agreement. As of December 31, 2015, the Company had outstanding borrowings of $18.8 million and letters of credit outstanding of $3.3 million. The Company recorded interest expense of $1.1 million, $0.5 million and $0.2 million in "Other income (expense), net" in the consolidated statements of operations for the years ended December 31, 2016, 2015 and 2014, respectively. 2012 Credit Agreement On November 30, 2012, CDI Corp., its direct wholly-owned subsidiary, CDI Corporation, and its indirect subsidiary, CDI AndersElite Limited, entered into a $75.0 million credit agreement (the “2012 Credit Agreement”) with Bank of America, N.A.. The 2012 Credit Agreement was terminated on October 30, 2015 with the execution of the 2015 Credit Agreement.

2015 Credit Agreement

On October 30, 2015, the Company and certain domestic subsidiaries (collectively with the Company, the “US Borrowers”), certain Canadian subsidiaries of the Company (collectively, the “Canadian Borrowers”), and certain UK subsidiaries of the Company (collectively, the “UK Borrowers”), collectively (the "Borrowers") entered into an agreement for a secured lending facility (the “2015 Credit Agreement”) with Bank of America, N.A. and other lenders. The 2015 Credit Agreement established a $150.0 million revolving line of credit facility which also includes an option to expand the facility by up to $75.0 million subject to agreement by the lenders, with a five-year term ending on October 30, 2020. In connection with the sale of Anders, the Company executed an amendment to the 2015 Credit Agreement to eliminate the UK Borrowers, release all liens and security interests on the UK collateral and allocate the available UK borrowings to the U.S. Borrowers. As of December 31, 2016, the facility is comprised of two subfacilities with $135.0 million available to the US Borrowers and $15.0 million available to the Canadian Borrowers. It also includes a $25.0 million sublimit for swingline loans and a $15.0 million sublimit for letters of credit.

Availability under the 2015 Credit Agreement is tied to a borrowing base, measured by 85% of eligible billed accounts receivable, plus 80% of eligible unbilled accounts receivable, less customary reserve amounts; provided however that the portion of the borrowing base consisting of 80% of the eligible unbilled accounts receivable may not exceed 30% of the sum of (i) 85% of the eligible billed accounts receivable, plus (ii) 80% of the eligible unbilled accounts receivable. Borrowings under the 2015 Credit Agreement may be used by the Company and the other Borrowers for general business purposes including capital expenditures and permitted acquisitions and investments. Accounts receivable, used in the determination of the borrowing base, are subject to lender discretion and, in certain circumstances, the lender may use cash balances in a dominion account established with the administrative agent to repay outstanding balances. As a result, amounts borrowed under the 2015 Credit Agreement are presented as current in the consolidated balance sheets.

The Borrowers’ obligations under the 2015 Credit Agreement are secured by a first lien security interest in all of the Borrowers’ personal property (subject to customary exceptions), including, among other things, accounts receivable, equity interests, deposit accounts, intellectual property, and leased properties where books and records are kept.

Interest on borrowings under the 2015 Credit Agreement is based on either (i) LIBOR plus an applicable margin (tied to the Borrowers’ excess availability under the facility) of 1.25% to 1.75% or (ii) the Federal Funds Rate/Bank’s Prime Rate plus an applicable margin of 0.25% to 0.75%, as selected by the applicable Borrower with respect to each borrowing. There are customary fees associated with the facility including an unused commitment fee of 0.25% per annum on the daily amount of unused commitments.

The 2015 Credit Agreement contains customary affirmative covenants, including with regard to financial reporting, and customary restrictive covenants. The 2015 Credit Agreement also contains a financial covenant which requires the Company’s fixed charge coverage ratio to exceed 1.0 to 1.0 if excess liquidity drops below an agreed threshold. The preceding financial covenant terms are further defined in the 2015 Credit Agreement. The Company was in compliance with all covenants under the 2015 Credit Agreement as of December 31, 2016 and December 31, 2015.

As of December 31, 2016, the Company had no outstanding borrowings, letters of credit outstanding of $3.3 million and $122.3 million available to borrow under the 2015 Credit Agreement. As of December 31, 2015, the Company had outstanding borrowings of $18.8 million and letters of credit outstanding of $3.3 million. The Company recorded interest expense of $1.1 million, $0.5 million and $0.2 million in "Other income (expense), net" in the consolidated statements of operations for the years ended December 31, 2016, 2015 and 2014, respectively.

2012 Credit Agreement

On November 30, 2012, CDI Corp., its direct wholly-owned subsidiary, CDI Corporation, and its indirect subsidiary, CDI AndersElite Limited, entered into a $75.0 million credit agreement (the “2012 Credit Agreement”) with Bank of America, N.A.. The 2012 Credit Agreement was terminated on October 30, 2015 with the execution of the 2015 Credit Agreement.