Segment Information (Total Assets by Segment) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	$ 1,080,264	$ 1,054,797
Healthcare [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	399,268	391,859
Energy [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	115,478	120,311
Financial Services Advisory and Compliance [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	95,534	98,846
Disputes, Forensics and Legal Technology [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	343,248	330,239
Unallocated Assets [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	$ 126,736	$ 113,542