Operating Segments and Related Information - Schedule of Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Segment information
Revenue, net	$ 47,074	$ 42,467	$ 38,510	$ 33,569	$ 39,183	$ 35,137	$ 35,291	$ 31,233	$ 161,620	$ 140,844	$ 138,302
Net income from continuing operations									4,556	2,229	1,539
Income tax expense	526	930	879	627	1,263	(685)	460	204	2,962	1,242	369
Interest expense, net	1,312	142	48	37	(98)	(14)	(12)	(29)	1,539	(153)	(190)
EBIT									9,057	3,318	1,718
Depreciation of property and equipment	1,107	1,133	1,109	1,220	1,209	1,376	1,216	1,232	4,569	5,033	5,317
Amortization of intangible assets	1,468	722	722	722	650	393	395	394	3,634	1,832	2,458
EBITDA									17,260	10,183	9,493
Foreign currency transaction (gains) losses on short-term intercompany balances	(263)	(418)	(957)	(552)	1,060	(165)	196	(1,007)	(2,190)	84	2,165
Acquisition-related charges									(2,283)
Transformation severance and related expenses									1,666	1,329	1,249
Other (income) loss	17	$ 17	$ 5	$ (199)	19	$ (168)	$ 18	$ 10	(160)	(121)	1,191
Stock-based compensation									7,052	5,123	3,926
Adjusted EBITDA									21,345	16,598	18,024
Capital expenditures									9,355	5,887	4,482
Allocated assets	97,357				73,035				97,357	73,035	59,540
Cash and cash equivalents	18,823				15,723				18,823	15,723	15,122	$ 25,735
Restricted cash	51				47				51	47
Deferred loan cost	131				0				131	0	80
Deferred income taxes	1,538				2,269				1,538	2,269
Total assets	120,218				93,474				120,218	93,474	80,391
Long-lived assets	54,006				37,550				54,006	37,550
Continuing operations
Segment information
Cash and cash equivalents	18,823				15,723				18,823	15,723	15,122
Restricted cash	51				47				51	47	48
Deferred income taxes	1,538				2,269				1,538	2,269	1,361
Prepaid expenses and other assets	910				800				910	800	2,465
Discontinued operations
Segment information
Discontinued operations	1,539				1,600				1,539	1,600	1,775
United States
Segment information
Revenue, net									93,447	80,857	80,484
Cash and cash equivalents	5,000								5,000
Long-lived assets	47,371				34,429				47,371	34,429
United Kingdom
Segment information
Revenue, net									23,408	17,501	19,540
Long-lived assets	5,510				2,047				5,510	2,047
Canada
Segment information
Revenue, net									14,375	14,531	12,388
Cash and cash equivalents	1,800								1,800
Australia
Segment information
Revenue, net									8,732	7,354	6,111
France
Segment information
Revenue, net									5,987	6,934	6,186
Mexico
Segment information
Revenue, net									5,385	4,900	4,340
Brazil
Segment information
Revenue, net									2,053	1,169	1,223
Spain
Segment information
Revenue, net									1,127	964	1,019
Ireland
Segment information
Revenue, net									929	337	513
New Zealand
Segment information
Revenue, net									899	979	596
Hong Kong
Segment information
Revenue, net									889	824	864
Colombia
Segment information
Revenue, net									709	583	610
Thailand
Segment information
Revenue, net									699	654	933
Other
Segment information
Revenue, net									2,981	3,257	3,495
Cash and cash equivalents	12,000								12,000
Other Segments [Member]
Segment information
Long-lived assets	1,125				1,074				1,125	1,074
Recovery Audit Services – Americas
Segment information
Revenue, net									113,122	99,861	97,009
EBIT									29,163	25,476	22,539
Depreciation of property and equipment									3,165	3,750	4,036
Amortization of intangible assets									1,919	1,477	1,728
EBITDA									34,247	30,703	28,303
Foreign currency transaction (gains) losses on short-term intercompany balances									(249)	31	807
Acquisition-related charges									0
Transformation severance and related expenses									313	517	322
Other (income) loss									751	0	0
Stock-based compensation									0	0	0
Adjusted EBITDA									35,062	31,251	29,432
Capital expenditures									2,389	4,393	3,669
Allocated assets	65,397				47,690				65,397	47,690	44,588
Total assets	65,397				47,690				65,397	47,690	44,588
Recovery Audit Services – Europe/Asia- Pacific
Segment information
Revenue, net									44,372	37,335	36,264
EBIT									11,700	6,455	2,573
Depreciation of property and equipment									599	529	647
Amortization of intangible assets									142	0	600
EBITDA									12,441	6,984	3,820
Foreign currency transaction (gains) losses on short-term intercompany balances									(1,769)	107	1,533
Acquisition-related charges									0
Transformation severance and related expenses									655	312	589
Other (income) loss									184	0	0
Stock-based compensation									0	0	0
Adjusted EBITDA									11,511	7,403	5,942
Capital expenditures									2,383	600	543
Allocated assets	22,474				14,813				22,474	14,813	13,922
Total assets	22,474				14,813				22,474	14,813	13,922
Adjacent Services
Segment information
Revenue, net									4,126	3,648	5,029
EBIT									(7,942)	(4,617)	(5,131)
Depreciation of property and equipment									805	754	634
Amortization of intangible assets									1,573	355	130
EBITDA									(5,564)	(3,508)	(4,367)
Foreign currency transaction (gains) losses on short-term intercompany balances									(9)	17	12
Acquisition-related charges									0
Transformation severance and related expenses									320	258	30
Other (income) loss									(195)	(121)	1,191
Stock-based compensation									0	0	0
Adjusted EBITDA									(5,448)	(3,354)	(3,134)
Capital expenditures									1,335	894	270
Allocated assets	9,486				10,532				9,486	10,532	1,030
Total assets	9,486				10,532				9,486	10,532	1,030
Corporate Support
Segment information
Revenue, net									0	0	0
EBIT									(23,864)	(23,996)	(18,263)
Depreciation of property and equipment									0	0	0
Amortization of intangible assets									0	0	0
EBITDA									(23,864)	(23,996)	(18,263)
Foreign currency transaction (gains) losses on short-term intercompany balances									(163)	(71)	(187)
Acquisition-related charges									(2,283)
Transformation severance and related expenses									378	242	308
Other (income) loss									(900)	0	0
Stock-based compensation									7,052	5,123	3,926
Adjusted EBITDA									(19,780)	(18,702)	(14,216)
Capital expenditures									3,248	0	0
Allocated assets	0				0				0	0	0
Total assets	22,861				20,439				22,861	20,439	20,851
Corporate Support | Continuing operations
Segment information
Cash and cash equivalents	18,823				15,723				18,823	15,723	15,122
Restricted cash	51				47				51	47	48
Deferred loan cost											80
Deferred income taxes	1,538				2,269				1,538	2,269	1,361
Prepaid expenses and other assets	910								910		2,465
Corporate Support | Discontinued operations
Segment information
Prepaid expenses and other assets					800					800
Discontinued operations	$ 1,539				$ 1,600				$ 1,539	$ 1,600	$ 1,775