Carrying amount as of the balance sheet date, which is the cumulative amount paid and (if applicable) the fair value of any noncontrolling interest in the acquiree, adjusted for any amortization recognized prior to the adoption of any changes in generally accepted accounting principles (as applicable) and for any impairment charges, in excess of the fair value of net assets acquired in one or more business combination transactions.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 142

-Paragraph 45

-Subparagraph e

-Clause 1

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 20

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=14024403&loc=d3e13816-109267

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

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Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 141R

-Paragraph 34

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 142

-Paragraph 43

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 7: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 142

-Paragraph 45

-Subparagraph e

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 8: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 141R

-Paragraph 72

-Subparagraph d

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

- Definition

The aggregate amount of goodwill acquired in the period and allocated to the reportable segment. The value is stated at fair value based on the purchase price allocation.

+ References+ Details

Goodwill and Intangible Assets, net (Schedule of Change in Carrying Values of Goodwill by segment) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012 Disputes, Investigations & Economics [Member]	Dec. 31, 2011 Disputes, Investigations & Economics [Member]	Dec. 31, 2012 Finance, Risk & Compliance Advisory [Member]	Dec. 31, 2011 Finance, Risk & Compliance Advisory [Member]	Dec. 31, 2012 Healthcare [Member]	Dec. 31, 2011 Healthcare [Member]	Dec. 31, 2012 Energy [Member]	Dec. 31, 2011 Energy [Member]	Dec. 31, 2011 Dispute and Investigative Services [Member]	Dec. 31, 2010 Dispute and Investigative Services [Member]	Dec. 31, 2011 Dispute and Investigative Services [Member] Disputes, Investigations & Economics [Member]	Dec. 31, 2010 Dispute and Investigative Services [Member] Disputes, Investigations & Economics [Member]	Dec. 31, 2011 Dispute and Investigative Services [Member] Finance, Risk & Compliance Advisory [Member]	Dec. 31, 2010 Dispute and Investigative Services [Member] Finance, Risk & Compliance Advisory [Member]	Dec. 31, 2011 Business Consulting Services [Member]	Dec. 31, 2010 Business Consulting Services [Member]	Dec. 31, 2011 Business Consulting Services [Member] Disputes, Investigations & Economics [Member]	Dec. 31, 2011 Business Consulting Services [Member] Finance, Risk & Compliance Advisory [Member]	Dec. 31, 2010 Business Consulting Services [Member] Finance, Risk & Compliance Advisory [Member]	Dec. 31, 2011 Business Consulting Services [Member] Healthcare [Member]	Dec. 31, 2010 Business Consulting Services [Member] Healthcare [Member]	Dec. 31, 2011 Business Consulting Services [Member] Energy [Member]	Dec. 31, 2010 Business Consulting Services [Member] Energy [Member]	Dec. 31, 2011 Consulting [Member]	Dec. 31, 2010 Consulting [Member]	Dec. 31, 2011 Consulting [Member] Disputes, Investigations & Economics [Member]	Dec. 31, 2010 Consulting [Member] Disputes, Investigations & Economics [Member]	Dec. 31, 2011 International Consulting [Member]	Dec. 31, 2010 International Consulting [Member]	Dec. 31, 2011 International Consulting [Member] Disputes, Investigations & Economics [Member]	Dec. 31, 2010 International Consulting [Member] Disputes, Investigations & Economics [Member]	Dec. 31, 2011 International Consulting [Member] Finance, Risk & Compliance Advisory [Member]	Dec. 31, 2010 International Consulting [Member] Finance, Risk & Compliance Advisory [Member]	Dec. 31, 2011 International Consulting [Member] Energy [Member]	Dec. 31, 2010 International Consulting [Member] Energy [Member]
Balance as of the beginning of the period - Goodwill, net	$ 570,280	$ 561,002	$ 326,458	$ 319,478	$ 56,962	$ 57,009	$ 115,527	$ 113,193	$ 71,333	$ 71,322	$ 263,200	$ 257,973	$ 226,934	$ 224,291	$ 36,266	$ 33,682	$ 195,303	$ 193,016	$ 2,584	$ 10,355	$ 12,986	$ 115,527	$ 113,193	$ 66,837	$ 66,837	$ 61,759	$ 61,759	$ 61,759	$ 61,759	$ 50,018	$ 48,254	$ 35,181	$ 33,428	$ 10,341	$ 10,341	$ 4,496	$ 4,485
Goodwill acquired during the period	45,870	10,102	26,900	7,757			13,704	2,334	5,266	11
Adjustments to goodwill	(189)	(189)	(142)	(142)	(47)	(47)
Foreign currency translation - Goodwill, net	3,971	(635)	3,971	(635)
Balance as of the end of the period - Goodwill, net	$ 619,932	$ 570,280	$ 357,187	$ 326,458	$ 56,915	$ 56,962	$ 129,231	$ 115,527	$ 76,599	$ 71,333	$ 263,200	$ 257,973	$ 226,934	$ 224,291	$ 36,266	$ 33,682	$ 195,303	$ 193,016	$ 2,584	$ 10,355	$ 12,986	$ 115,527	$ 113,193	$ 66,837	$ 66,837	$ 61,759	$ 61,759	$ 61,759	$ 61,759	$ 50,018	$ 48,254	$ 35,181	$ 33,428	$ 10,341	$ 10,341	$ 4,496	$ 4,485