ACQUISITIONS (Details) (USD $)	12 Months Ended			0 Months Ended	12 Months Ended				12 Months Ended				0 Months Ended			1 Months Ended	12 Months Ended		1 Months Ended				0 Months Ended	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 28, 2011 De Novo Legal LLC	Dec. 31, 2012 De Novo Legal LLC	Dec. 31, 2011 De Novo Legal LLC	Dec. 31, 2012 De Novo Legal LLC Contingent consideration - purchase price consideration	Dec. 28, 2011 De Novo Legal LLC Contingent consideration - purchase price consideration	Dec. 31, 2012 De Novo Legal LLC Contingent consideration - continued employment	Dec. 31, 2011 De Novo Legal LLC Long-term Obligations	Dec. 31, 2011 De Novo Legal LLC Long-term Obligations Contingent consideration - purchase price consideration	Dec. 31, 2012 De Novo Legal LLC Current maturities of long-term obligations	Dec. 28, 2011 De Novo Legal LLC Trade names	Dec. 28, 2011 De Novo Legal LLC Non-compete agreements	Dec. 28, 2011 De Novo Legal LLC Customer relationships	Apr. 04, 2011 Encore Discovery Solutions	Dec. 31, 2012 Encore Discovery Solutions	Dec. 31, 2011 Encore Discovery Solutions	Apr. 04, 2011 Encore Discovery Solutions Trade names	Apr. 04, 2011 Encore Discovery Solutions Non-compete agreements	Apr. 04, 2011 Encore Discovery Solutions Customer relationships	Apr. 04, 2011 Encore Discovery Solutions AACER software application	Oct. 01, 2010 Jupiter eSources	Dec. 31, 2011 Jupiter eSources	Dec. 31, 2012 Jupiter eSources Contingent consideration - purchase price consideration	Oct. 01, 2010 Jupiter eSources Contingent consideration - purchase price consideration	Dec. 31, 2011 Jupiter eSources Current maturities of long-term obligations
Acquisitions
Percentage interest acquired in acquisition				100.00%												100.00%
Amount held as security for potential indemnification claims																$ 10,000,000
Amount withheld as security at the acquisition date for potential indemnification claims				5,000,000																			8,400,000
Total preliminary purchase price transferred to effect the acquisition
Cash paid at closing				67,866,000												103,385,000
Other consideration		29,447,000	15,256,000													844,000
Fair value of deferred cash consideration				4,417,000
Fair value of contingent consideration				16,226,000
Working capital adjustment				(1,861,000)												98,000
Total purchase price				86,648,000												104,327,000							67,400,000
Period of deferral of purchase price held by company following closing date				18 months																			18 months
Discount rate used in determining fair value of deferred cash consideration (as a percent)				11.00%
Holdback amount recorded in long-term obligations										4,900,000		0															8,300,000
Potential undiscounted amount of all future payments, minimum								0																		0
Potential undiscounted amount of all future payments, maximum								29,100,000																		20,000,000
Period over which potential undiscounted amount of all future payments are required							2 years																		4 years
Portion of earn-out opportunity contingent upon certain of sellers remaining employees of company	1
Portion of contingent consideration not contingent upon employment recorded in financial statements											16,200,000
Compensation expense related to portion of the contingent consideration tied to employment reflected in general and administrative expense					0	0
Adjustment to contingent consideration liability							17,200,000		3,400,000
Change in fair value accretion expense included in interest expense							1,100,000
Change in fair value depletion expense included in Other operating expense																								7,200,000
Changes in preliminary purchase price allocation to reflect changes in fair value of property, plant and equipment acquired					1,500,000
Changes in preliminary purchase price allocation to reflect changes in fair value of intangibles acquired					200,000												32,600,000
Changes in preliminary purchase price allocation to reflect changes in fair value of goodwill acquired	1,276,000				1,300,000
Transaction related costs	(200,000)	7,681,000	2,125,000			3,500,000												3,900,000						2,600,000
Tangible assets and liabilities
Current assets, including cash acquired				11,214,000												20,044,000
Non-current assets				2,738,000												2,669,000
Current liabilities				(2,361,000)												(6,646,000)
Non-current liabilities				(500,000)												(15,115,000)
Intangible assets				34,629,000												32,578,000
Software																2,498,000
Goodwill	404,200,000			40,928,000												68,299,000
Net assets acquired				86,648,000												104,327,000
Preliminary net deferred tax liability																16,000,000
Major classes of acquired intangible assets and software, as well as the respective weighted-average amortization periods
Identifiable intangible assets, Amount				34,629,000									850,000	2,900,000	30,879,000	32,578,000			1,617,000	1,362,000	29,599,000
Identifiable intangible assets, Weighted Average Amortization Period													5 years	5 years	8 years				5 years	2 years	7 years	5 years
Software internally developed, Amount	18,905,000	21,195,000																			2,498,000
Operating revenue																42,200,000							3,800,000
Operating loss																8,300,000							900,000
Decrease in net deferred tax liability																16,000,000
Pro forma financial information
Total revenue		356,954,000	340,425,000
Operating revenue		334,893,000	310,854,000
Net income		22,759,000	16,346,000
Impairment expenses of intangible asset related to trade name																								$ 1,300,000