Segment Information (Schedule of Segment Revenues Before Reimbursements, Segment Total Revenues and Segment Operating Profit) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Total revenues before reimbursements	$ 743,383	$ 695,714	$ 623,461
Total revenues	844,641	784,684	703,660
Total combined segment operating profit	264,532	243,199	215,915
General and administrative expenses	141,155	130,415	121,685
Depreciation expense	14,986	13,303	14,457
Amortization expense	6,767	8,658	12,368
Long-term compensation expense related to consulting personnel (including share-based compensation)	16,121	14,530	10,977
Other operating costs	1,645		6,407
Operating income	83,858	76,293	50,021
Other expense, net	4,503	5,566	8,828
Income before income tax expense	79,355	70,727	41,193
Finance, Risk & Compliance Advisory [Member]
Total revenues before reimbursements	162,614	136,472	98,288
Total revenues	204,166	159,663	112,830
Total combined segment operating profit	58,564	44,906	31,197
Disputes, Investigations & Economics [Member]
Total revenues before reimbursements	340,036	338,965	344,548
Total revenues	364,426	370,850	379,846
Total combined segment operating profit	123,288	122,672	118,459
Healthcare [Member]
Total revenues before reimbursements	151,065	134,611	105,933
Total revenues	170,150	151,841	122,807
Total combined segment operating profit	50,959	42,739	37,348
Energy [Member]
Total revenues before reimbursements	89,668	85,666	74,692
Total revenues	105,899	102,330	88,177
Total combined segment operating profit	$ 31,721	$ 32,882	$ 28,911