Segment Information (Details) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2016 USD ($)	Sep. 30, 2015 USD ($)	Sep. 30, 2016 USD ($) segment	Sep. 30, 2015 USD ($)
Segment Reporting, Reconciling Item for Operating Profit from Segment to Consolidated
Revenues	$ 277,286	$ 293,335	$ 836,863	$ 885,510
Reimbursements	18,101	16,649	47,101	55,506
Total revenues	295,387	309,984	883,964	941,016
Net corporate interest expense	(2,262)	(2,332)	(7,553)	(6,238)
Restructuring and special charges	(1,488)	(11,078)	(7,431)	(16,383)
Income before income taxes	19,955	7,298	$ 49,168	21,707
Number of operating segments (segments) \| segment			4
Operating Segments
Segment Reporting, Reconciling Item for Operating Profit from Segment to Consolidated
Total segment operating earnings	33,229	27,391	$ 89,289	63,115
Corporate, Non-Segment
Segment Reporting, Reconciling Item for Operating Profit from Segment to Consolidated
Unallocated corporate and shared costs, net	(6,947)	(4,303)	(17,454)	(11,648)
Net corporate interest expense	(2,262)	(2,332)	(7,553)	(6,238)
Stock option expense	(176)	(30)	(403)	(357)
Restructuring and special charges	(1,488)	(11,078)	(7,431)	(16,383)
Corporate, Non-Segment \| Customer relationships and trade names
Segment Reporting, Reconciling Item for Operating Profit from Segment to Consolidated
Amortization of customer-relationship intangible assets	(2,401)	(2,350)	(7,280)	(6,782)
U.S. Services
Segment Reporting, Reconciling Item for Operating Profit from Segment to Consolidated
Revenues	56,470	62,080	173,813	185,683
U.S. Services \| Operating Segments
Segment Reporting, Reconciling Item for Operating Profit from Segment to Consolidated
Revenues	56,470	62,080	173,813	185,683
Total segment operating earnings	9,379	10,841	28,012	24,837
International \| Operating Segments
Segment Reporting, Reconciling Item for Operating Profit from Segment to Consolidated
Revenues	121,644	128,198	362,401	381,706
Total segment operating earnings	13,236	7,974	31,243	11,484
Broadspire
Segment Reporting, Reconciling Item for Operating Profit from Segment to Consolidated
Revenues	76,676	74,225	227,975	217,590
Broadspire \| Operating Segments
Segment Reporting, Reconciling Item for Operating Profit from Segment to Consolidated
Revenues	76,676	74,225	227,975	217,590
Total segment operating earnings	8,263	7,435	23,497	16,981
Garden City Group \| Operating Segments
Segment Reporting, Reconciling Item for Operating Profit from Segment to Consolidated
Revenues	22,496	28,832	72,674	100,531
Total segment operating earnings	$ 2,351	$ 1,141	$ 6,537	$ 9,813

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