Commitments And Contingencies	6 Months Ended
Jun. 30, 2014
Commitments and Contingencies Disclosure [Abstract]
Commitments And Contingencies	Commitments and Contingencies In the normal course of business, the Company is party to various claims and legal proceedings. SEI has been named in six lawsuits filed in Louisiana. Five lawsuits were filed in the 19th Judicial District Court for the Parish of East Baton Rouge, State of Louisiana. One of the five actions purports to set forth claims on behalf of a class and also names SPTC as a defendant and, as described below, was certified as a class in December 2012. Two of the other actions also name SPTC as a defendant. All five actions name various defendants in addition to SEI, and, in all five actions, the plaintiffs purport to bring a cause of action against SEI and SPTC under the Louisiana Securities Act. The class action originally included a claim against SEI and SPTC for an alleged violation of the Louisiana Unfair Trade Practices Act. Two of the other five actions include claims for violations of the Louisiana Racketeering Act and possibly conspiracy. In addition, another group of plaintiffs filed a lawsuit in the 23rd Judicial District Court for the Parish of Ascension, State of Louisiana, against SEI and SPTC and other defendants asserting claims of negligence, breach of contract, breach of fiduciary duty, violations of the uniform fiduciaries law, negligent misrepresentation, detrimental reliance, violations of the Louisiana Securities Act and Louisiana Racketeering Act and conspiracy. The underlying allegations in all the actions are purportedly related to the role of SPTC in providing back-office services to Stanford Trust Company. The petitions allege that SEI and SPTC aided and abetted or otherwise participated in the sale of “certificates of deposit” issued by Stanford International Bank. Two of the five actions filed in East Baton Rouge were removed to federal court and transferred by the Judicial Panel on Multidistrict Litigation to United States District Court for the Northern District of Texas. On August 31, 2011, the United States District Court for the Northern District of Texas issued an order and judgment that the causes of action alleged against SEI in the two removed actions were preempted by federal law and the court dismissed these cases with prejudice. Plaintiffs appealed this ruling, and on March 19, 2012, a panel of the Court of Appeals for the Fifth Circuit reversed the decision of the United States District Court and remanded the actions for further proceedings. On July 18, 2012, SEI filed a petition for a writ of certiorari in the United States Supreme Court, seeking review of the decision by the United States Court of Appeals in the Fifth Circuit to permit the claims against SEI to proceed. SEI believes that the trial court correctly concluded that the claims against SEI were barred by the federal Securities Litigation Uniform Standards Act and requested that the Supreme Court reinstate that dismissal. On January 18, 2013, the Supreme Court granted the petition for a writ of certiorari. On October 7, 2013, the Supreme Court heard oral argument on the appeal and on February 26, 2014 the Supreme Court affirmed the judgment of the Court of Appeals. The case filed in Ascension was also removed to federal court and transferred by the Judicial Panel on Multidistrict Litigation to the Northern District of Texas. The schedule for responding to that complaint has not yet been established. The plaintiffs in the remaining two cases in East Baton Rouge have granted SEI and SPTC an extension to respond to the filings. SEI and SPTC filed exceptions in the class action pending in East Baton Rouge, which the Court granted in part and dismissed the claims under the Louisiana Unfair Trade Practices Act and denied in part as to the other exceptions. SEI and SPTC filed an answer to the East Baton Rouge class action, plaintiffs filed a motion for class certification; and SEI and SPTC also filed a motion for summary judgment against certain named plaintiffs which the Court stated would not be set for hearing until after the hearing on the class certification motion. The Court in the East Baton Rouge action held a hearing on class certification on September 20, 2012. By oral decision on December 5, 2012 and later entered in a judgment signed on December 17, 2012 that was subsequently amended, the Court in East Baton Rouge certified a class to be composed of persons who purchased any Stanford International Bank certificates of deposit (SIB CDs) in Louisiana between January 1, 2007 and February 13, 2009; persons who renewed any SIB CD in Louisiana between January 1, 2007 and February 13, 2009; or any person for whom the Stanford Trust Company purchased SIB CDs in Louisiana between January 1, 2007 and February 13, 2009. On January 30, 2013, SEI and SPTC filed motions for appeal from the judgments that stated SEI's and SPTC's intention to move to stay the litigation. On February 1, 2013, plaintiffs filed a motion for Leave to File First Amended and Restated Class Action Petition in which they ask the Court to allow them to amend the petition in this case to add additional facts that were developed during discovery and adding claims against certain of SEI's insurance carriers. On February 5, 2013, the Court granted two of the motions for appeal and the motion for leave to amend. On February 15, 2013, SEI filed a motion for new trial, or, in the alternative, for reconsideration of the Court's order allowing amendment. On February 22, 2013, SEI filed a motion to stay proceedings in view of the pending Supreme Court case. On February 28, 2013, SEI responded to the First Amended and Restated Class Action Petition by filing an exception. On March 11, 2013, the insurance carrier defendants filed a notice of removal removing the case to the Middle District of Louisiana and on March 18, 2013, the insurance carrier defendants filed answers. On March 13, 2013, SEI notified the Judicial Panel on Multidistrict Litigation (MDL) of this case as a potential tag-along action. On March 19, 2013, plaintiffs filed a motion to remand, a motion for expedited briefing schedule, expedited status conference and expedited consideration of their motion to remand, a motion for leave to file under seal and a motion for order pursuant to 28 U.S.C. 1447(b) requiring removing defendants to supplement federal court record with certified copy of state court record. These motions are now fully briefed. On March 25, 2013, SEI filed a motion that the court decline to adopt the state court's order regarding class certification, which the court dismissed without prejudice to renew upon a determination of removal jurisdiction in an April 12, 2013 order that also dismissed without prejudice a motion to dismiss for lack of jurisdiction and improper venue filed on April 9, 2013 by one of the insurers. On April 1, 2013, the Louisiana Office of Financial Institutions (OFI) filed a motion to remand and sever claims, and a response to that motion by the insurers and opposition to that motion by the plaintiffs were filed on April 22, 2013. Along with the briefing in the Middle District of Louisiana, on March 13, 2013, SEI notified the MDL of this case as a potential tag-along action. On March 19, 2013, plaintiffs notified the MDL that they had filed a motion to remand and asked the panel to decline to issue a conditional transfer order. On March 29, 2013, the MDL issued a conditional transfer order (CTO). On April 18, 2013, OFI filed a motion to vacate the CTO or, in the alternative, stay any ruling to transfer the matter until after the Middle District of Louisiana ruled on OFI's motion to remand and sever. Plaintiffs filed a motion to vacate the CTO on April 19, 2013. SEI's responses to those motions were filed on May 9, 2013. On June 12, 2013, the MDL Panel issued an order notifying the parties that on July 25, 2013, it would consider, without oral argument, Plaintiffs' and OFI's motions to vacate the CTO. On August 7, 2013, the MDL Panel affirmed the CTO and transferred the matter against SEI to the United States District Court for the Northern District of Texas; the MDL Panel also severed the claims against OFI and remanded those claims to the Middle District of Louisiana. On September 11, 2013, defendants filed a motion requesting a status conference with the Court to address the status of all pending motions. On October 4, 2013, Plaintiffs filed a petition for a writ of mandamus asking the United States Court of Appeals for the Fifth Circuit to review the MDL Panel’s transfer Order and on February 14, 2014, the Court denied the petition. While the outcome of this litigation is uncertain given its early phase, SEI and SPTC believe that they have valid defenses to plaintiffs' claims and intend to defend the lawsuits vigorously. Because of the uncertainty of the make-up of the classes, the specific theories of liability that may survive a motion for summary judgment or other dispositive motion, the lack of discovery regarding damages, causation, mitigation and other aspects that may ultimately bear upon loss, the Company is not reasonably able to provide an estimate of loss, if any, with respect to the foregoing lawsuits. A lawsuit entitled Steven Curd and Rebel Curd v. SEI Investments Management Corporation (SIMC) was filed against SIMC in the United States District Court for the Eastern District of Pennsylvania on December 11, 2013. The plaintiffs bring the case as a shareholder derivative action against SIMC on behalf of certain SEI funds. The claims are based on Section 36(b) of the Investment Company Act of 1940, as amended, which allows shareholders of a mutual fund to sue the investment adviser of the fund for an alleged breach of fiduciary duty with respect to compensation received by the adviser. The plaintiffs have brought the suit against SIMC with respect to five specific SEI Funds: the High Yield Bond, Tax-Managed Large Cap, and Tax-Managed Small/Mid Cap Funds, each of which is a series of the SEI Institutional Managed Trust, the Intermediate Term Municipal Fund, which is a series of the SEI Tax Exempt Trust, and the International Equity Fund, which is a series of the SEI Institutional International Trust ("the SEI Funds"). The plaintiffs seek: (1) damages for the SEI Funds in the amount of the alleged “excessive” fees earned by SIMC beginning from the one year period prior to the filing of the lawsuit, plus interest, costs, and fees; (2) orders declaring that SIMC allegedly violated Section 36(b) and enjoining SIMC from further alleged violations; and (3) rescission of the advisory contracts between SIMC and the funds, and restitution of all allegedly excessive fees paid beginning from the one year period prior to the filing of the lawsuit, plus interest, costs, and fees. On February 24, 2014, SIMC filed a motion to dismiss the complaint in this lawsuit. The plaintiffs named the SEI Funds as nominal defendants, and the SEI Funds moved to dismiss on May 23, 2014. While the outcome of this litigation is uncertain given its early phase, SIMC believes that it has valid defenses to plaintiffs' claims and intends to defend the lawsuit vigorously and SIMC is not reasonably able to provide an estimate of the ultimate loss, if any, with respect to this lawsuit.

Commitments and Contingencies

In the normal course of business, the Company is party to various claims and legal proceedings.

SEI has been named in six lawsuits filed in Louisiana. Five lawsuits were filed in the 19th Judicial District Court for the Parish of East Baton Rouge, State of Louisiana. One of the five actions purports to set forth claims on behalf of a class and also names SPTC as a defendant and, as described below, was certified as a class in December 2012. Two of the other actions also name SPTC as a defendant. All five actions name various defendants in addition to SEI, and, in all five actions, the plaintiffs purport to bring a cause of action against SEI and SPTC under the Louisiana Securities Act. The class action originally included a claim against SEI and SPTC for an alleged violation of the Louisiana Unfair Trade Practices Act. Two of the other five actions include claims for violations of the Louisiana Racketeering Act and possibly conspiracy. In addition, another group of plaintiffs filed a lawsuit in the 23rd Judicial District Court for the Parish of Ascension, State of Louisiana, against SEI and SPTC and other defendants asserting claims of negligence, breach of contract, breach of fiduciary duty, violations of the uniform fiduciaries law, negligent misrepresentation, detrimental reliance, violations of the Louisiana Securities Act and Louisiana Racketeering Act and conspiracy. The underlying allegations in all the actions are purportedly related to the role of SPTC in providing back-office services to Stanford Trust Company. The petitions allege that SEI and SPTC aided and abetted or otherwise participated in the sale of “certificates of deposit” issued by Stanford International Bank.

Two of the five actions filed in East Baton Rouge were removed to federal court and transferred by the Judicial Panel on Multidistrict Litigation to United States District Court for the Northern District of Texas. On August 31, 2011, the United States District Court for the Northern District of Texas issued an order and judgment that the causes of action alleged against SEI in the two removed actions were preempted by federal law and the court dismissed these cases with prejudice. Plaintiffs appealed this ruling, and on March 19, 2012, a panel of the Court of Appeals for the Fifth Circuit reversed the decision of the United States District Court and remanded the actions for further proceedings. On July 18, 2012, SEI filed a petition for a writ of certiorari in the United States Supreme Court, seeking review of the decision by the United States Court of Appeals in the Fifth Circuit to permit the claims against SEI to proceed. SEI believes that the trial court correctly concluded that the claims against SEI were barred by the federal Securities Litigation Uniform Standards Act and requested that the Supreme Court reinstate that dismissal. On January 18, 2013, the Supreme Court granted the petition for a writ of certiorari. On October 7, 2013, the Supreme Court heard oral argument on the appeal and on February 26, 2014 the Supreme Court affirmed the judgment of the Court of Appeals.

The case filed in Ascension was also removed to federal court and transferred by the Judicial Panel on Multidistrict Litigation to the Northern District of Texas. The schedule for responding to that complaint has not yet been established. The plaintiffs in the remaining two cases in East Baton Rouge have granted SEI and SPTC an extension to respond to the filings. SEI and SPTC filed exceptions in the class action pending in East Baton Rouge, which the Court granted in part and dismissed the claims under the Louisiana Unfair Trade Practices Act and denied in part as to the other exceptions.

SEI and SPTC filed an answer to the East Baton Rouge class action, plaintiffs filed a motion for class certification; and SEI and SPTC also filed a motion for summary judgment against certain named plaintiffs which the Court stated would not be set for hearing until after the hearing on the class certification motion. The Court in the East Baton Rouge action held a hearing on class certification on September 20, 2012. By oral decision on December 5, 2012 and later entered in a judgment signed on December 17, 2012 that was subsequently amended, the Court in East Baton Rouge certified a class to be composed of persons who purchased any Stanford International Bank certificates of deposit (SIB CDs) in Louisiana between January 1, 2007 and February 13, 2009; persons who renewed any SIB CD in Louisiana between January 1, 2007 and February 13, 2009; or any person for whom the Stanford Trust Company purchased SIB CDs in Louisiana between January 1, 2007 and February 13, 2009. On January 30, 2013, SEI and SPTC filed motions for appeal from the judgments that stated SEI's and SPTC's intention to move to stay the litigation. On February 1, 2013, plaintiffs filed a motion for Leave to File First Amended and Restated Class Action Petition in which they ask the Court to allow them to amend the petition in this case to add additional facts that were developed during discovery and adding claims against certain of SEI's insurance carriers. On February 5, 2013, the Court granted two of the motions for appeal and the motion for leave to amend. On February 15, 2013, SEI filed a motion for new trial, or, in the alternative, for reconsideration of the Court's order allowing amendment. On February 22, 2013, SEI filed a motion to stay proceedings in view of the pending Supreme Court case. On February 28, 2013, SEI responded to the First Amended and Restated Class Action Petition by filing an exception. On March 11, 2013, the insurance carrier defendants filed a notice of removal removing the case to the Middle District of Louisiana and on March 18, 2013, the insurance carrier defendants filed answers. On March 13, 2013, SEI notified the Judicial Panel on Multidistrict Litigation (MDL) of this case as a potential tag-along action. On March 19, 2013, plaintiffs filed a motion to remand, a motion for expedited briefing schedule, expedited status conference and expedited consideration of their motion to remand, a motion for leave to file under seal and a motion for order pursuant to 28 U.S.C. 1447(b) requiring removing defendants to supplement federal court record with certified copy of state court record. These motions are now fully briefed. On March 25, 2013, SEI filed a motion that the court decline to adopt the state court's order regarding class certification, which the court dismissed without prejudice to renew upon a determination of removal jurisdiction in an April 12, 2013 order that also dismissed without prejudice a motion to dismiss for lack of jurisdiction and improper venue filed on April 9, 2013 by one of the insurers. On April 1, 2013, the Louisiana Office of Financial Institutions (OFI) filed a motion to remand and sever claims, and a response to that motion by the insurers and opposition to that motion by the plaintiffs were filed on April 22, 2013. Along with the briefing in the Middle District of Louisiana, on March 13, 2013, SEI notified the MDL of this case as a potential tag-along action. On March 19, 2013, plaintiffs notified the MDL that they had filed a motion to remand and asked the panel to decline to issue a conditional transfer order. On March 29, 2013, the MDL issued a conditional transfer order (CTO). On April 18, 2013, OFI filed a motion to vacate the CTO or, in the alternative, stay any ruling to transfer the matter until after the Middle District of Louisiana ruled on OFI's motion to remand and sever. Plaintiffs filed a motion to vacate the CTO on April 19, 2013. SEI's responses to those motions were filed on May 9, 2013. On June 12, 2013, the MDL Panel issued an order notifying the parties that on July 25, 2013, it would consider, without oral argument, Plaintiffs' and OFI's motions to vacate the CTO. On August 7, 2013, the MDL Panel affirmed the CTO and transferred the matter against SEI to the United States District Court for the Northern District of Texas; the MDL Panel also severed the claims against OFI and remanded those claims to the Middle District of Louisiana. On September 11, 2013, defendants filed a motion requesting a status conference with the Court to address the status of all pending motions. On October 4, 2013, Plaintiffs filed a petition for a writ of mandamus asking the United States Court of Appeals for the Fifth Circuit to review the MDL Panel’s transfer Order and on February 14, 2014, the Court denied the petition.

While the outcome of this litigation is uncertain given its early phase, SEI and SPTC believe that they have valid defenses to plaintiffs' claims and intend to defend the lawsuits vigorously. Because of the uncertainty of the make-up of the classes, the specific theories of liability that may survive a motion for summary judgment or other dispositive motion, the lack of discovery regarding damages, causation, mitigation and other aspects that may ultimately bear upon loss, the Company is not reasonably able to provide an estimate of loss, if any, with respect to the foregoing lawsuits.

A lawsuit entitled Steven Curd and Rebel Curd v. SEI Investments Management Corporation (SIMC) was filed against SIMC in the United States District Court for the Eastern District of Pennsylvania on December 11, 2013. The plaintiffs bring the case as a shareholder derivative action against SIMC on behalf of certain SEI funds. The claims are based on Section 36(b) of the Investment Company Act of 1940, as amended, which allows shareholders of a mutual fund to sue the investment adviser of the fund for an alleged breach of fiduciary duty with respect to compensation received by the adviser. The plaintiffs have brought the suit against SIMC with respect to five specific SEI Funds: the High Yield Bond, Tax-Managed Large Cap, and Tax-Managed Small/Mid Cap Funds, each of which is a series of the SEI Institutional Managed Trust, the Intermediate Term Municipal Fund, which is a series of the SEI Tax Exempt Trust, and the International Equity Fund, which is a series of the SEI Institutional International Trust ("the SEI Funds"). The plaintiffs seek: (1) damages for the SEI Funds in the amount of the alleged “excessive” fees earned by SIMC beginning from the one year period prior to the filing of the lawsuit, plus interest, costs, and fees; (2) orders declaring that SIMC allegedly violated Section 36(b) and enjoining SIMC from further alleged violations; and (3) rescission of the advisory contracts between SIMC and the funds, and restitution of all allegedly excessive fees paid beginning from the one year period prior to the filing of the lawsuit, plus interest, costs, and fees. On February 24, 2014, SIMC filed a motion to dismiss the complaint in this lawsuit. The plaintiffs named the SEI Funds as nominal defendants, and the SEI Funds moved to dismiss on May 23, 2014. While the outcome of this litigation is uncertain given its early phase, SIMC believes that it has valid defenses to plaintiffs' claims and intends to defend the lawsuit vigorously and SIMC is not reasonably able to provide an estimate of the ultimate loss, if any, with respect to this lawsuit.