Business Segments (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014 segment	Sep. 30, 2013
Segment Reporting [Abstract]
Number of reportable business segments			5
Segment Reporting Information [Line Items]
Revenue	$ 123,869	$ 113,197	$ 376,667	$ 319,469
Gain on change in fair value of contingent consideration, net	655	135	1,513	427
Operating income	11,310	10,340	32,239	26,239
Interest expense	117	90	399	256
Other income (expense)	(72)	4	185	326
Income before income tax expense	11,121	10,254	32,025	26,309
Learning Solutions [Member]
Segment Reporting Information [Line Items]
Revenue	60,811	49,304	175,748	137,223
Operating income	3,045	4,120	7,356	10,886
Professional and Technical Services [Member]
Segment Reporting Information [Line Items]
Revenue	20,226	19,157	58,925	54,220
Operating income	2,383	1,530	6,384	4,335
Sandy Training and Marketing [Member]
Segment Reporting Information [Line Items]
Revenue	15,883	16,929	50,364	52,061
Operating income	1,023	975	3,204	2,797
Performance Readiness Solutions [Member]
Segment Reporting Information [Line Items]
Revenue	13,315	13,037	40,454	41,491
Operating income	1,354	907	2,953	1,802
Energy Services [Member]
Segment Reporting Information [Line Items]
Revenue	13,634	14,770	51,176	34,474
Operating income	$ 2,850	$ 2,673	$ 10,829	$ 5,992