FAIR VALUE MEASUREMENTS (asset impairment analyses) (Details) $ in Thousands		3 Months Ended										6 Months Ended	12 Months Ended
		Dec. 31, 2019 USD ($)	Sep. 30, 2019 USD ($) reporting_units	Jun. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Sep. 30, 2018 USD ($) reporting_units		Jun. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Sep. 30, 2017 USD ($)	Jun. 30, 2017 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($) business	Dec. 31, 2017 USD ($)	Dec. 31, 2015 business	Jul. 31, 2019 USD ($)	Jul. 31, 2018 USD ($)	Jul. 31, 2017 USD ($)
Schedule of asset impairment analyses [Line Items]
Goodwill impairment charge			$ 357,741										$ 357,741	$ 78,188
Goodwill		$ 804,487				$ 1,160,626							804,487	1,160,626	$ 1,130,934
Carrying value of indefinite-lived trade name																			$ 19,100
Excess of fair value over carrying value of indefinite-lived trade name																			16,000
Impairment charges, assets held for sale												$ 8,250
Total asset impairment charges		0	390,980	$ 0	$ 0	0	$ 99,170		$ 0	$ 2,149			390,980	101,319	54,880
Reportable business segments [Member] | Small Business Services [Member]
Schedule of asset impairment analyses [Line Items]
Goodwill impairment charge													242,267	78,188
Goodwill		395,286				638,699							395,286	638,699	658,189
Total asset impairment charges													273,583	$ 99,437	54,880
Reportable business segments [Member] | Small Business Services [Member] | Small business distributors [Member]
Schedule of asset impairment analyses [Line Items]
Number of businesses acquired | business														3
Reportable business segments [Member] | Financial Services [Member]
Schedule of asset impairment analyses [Line Items]
Goodwill impairment charge													115,474
Goodwill		$ 260,695				373,421							260,695	$ 373,421	324,239
Total asset impairment charges													$ 117,397	1,882	$ 0
Reportable business segments [Member] | Financial Services [Member] | Small business distributors [Member]
Schedule of asset impairment analyses [Line Items]
Number of businesses acquired | business																2
Measurement input, royalty rate [Member]
Schedule of asset impairment analyses [Line Items]
Intangibles fair value inputs																		0.00%
Nonrecurring [Member] | Intangible assets [Member] | Reportable business segments [Member] | Small Business Services [Member]
Schedule of asset impairment analyses [Line Items]
Asset impairment charges	[1]		31,316
Fair value as of measurement date	[2]																$ 8,379
Nonrecurring [Member] | Trade names [Member] | Reportable business segments [Member] | Small Business Services [Member]
Schedule of asset impairment analyses [Line Items]
Asset impairment charges											$ 14,752
Fair value as of measurement date											0
Nonrecurring [Member] | Customer lists/relationships [Member] | Reportable business segments [Member] | Small Business Services [Member]
Schedule of asset impairment analyses [Line Items]
Asset impairment charges										2,149
Fair value as of measurement date										0
Nonrecurring [Member] | Customer lists/relationships [Member] | Reportable business segments [Member] | Financial Services [Member]
Schedule of asset impairment analyses [Line Items]
Asset impairment charges			1,923				1,882
Fair value as of measurement date			0				4,223	[2]
Significant unobservable inputs (Level 3) [Member] | Nonrecurring [Member] | Intangible assets [Member] | Reportable business segments [Member] | Small Business Services [Member]
Schedule of asset impairment analyses [Line Items]
Fair value as of measurement date	[2]																8,379
Significant unobservable inputs (Level 3) [Member] | Nonrecurring [Member] | Trade names [Member] | Reportable business segments [Member] | Small Business Services [Member]
Schedule of asset impairment analyses [Line Items]
Fair value as of measurement date											0
Significant unobservable inputs (Level 3) [Member] | Nonrecurring [Member] | Customer lists/relationships [Member] | Reportable business segments [Member] | Small Business Services [Member]
Schedule of asset impairment analyses [Line Items]
Fair value as of measurement date										$ 0
Significant unobservable inputs (Level 3) [Member] | Nonrecurring [Member] | Customer lists/relationships [Member] | Reportable business segments [Member] | Financial Services [Member]
Schedule of asset impairment analyses [Line Items]
Fair value as of measurement date			$ 0				$ 4,223	[2]
Reporting units for which qualitative analysis completed [Member]
Schedule of asset impairment analyses [Line Items]
Number of reporting units | reporting_units			4				5
Reporting units for which qualitative analysis completed [Member] | Minimum [Member]
Schedule of asset impairment analyses [Line Items]
Excess of fair value over carrying value of reporting unit's net assets																			$ 64,000
Excess of fair value over carrying value of reporting unit, percentage																			50.00%
Reporting units for which qualitative analysis completed [Member] | Maximum [Member]
Schedule of asset impairment analyses [Line Items]
Excess of fair value over carrying value of reporting unit's net assets																			$ 1,405,000
Excess of fair value over carrying value of reporting unit, percentage																			314.00%
Reporting units for which quantitative analysis completed [Member]
Schedule of asset impairment analyses [Line Items]
Number of reporting units | reporting_units			2				2
Reporting units for which quantitative analysis completed [Member] | Minimum [Member]
Schedule of asset impairment analyses [Line Items]
Excess of fair value over carrying value of reporting unit's net assets																			$ 64,000
Excess of fair value over carrying value of reporting unit, percentage																			36.00%
Reporting units for which quantitative analysis completed [Member] | Maximum [Member]
Schedule of asset impairment analyses [Line Items]
Excess of fair value over carrying value of reporting unit's net assets																			$ 1,405,000
Excess of fair value over carrying value of reporting unit, percentage																			314.00%
Financial Servcices Data-Driven Marketing [Member]
Schedule of asset impairment analyses [Line Items]
Goodwill impairment charge			$ 115,474
Goodwill						186,388								186,388			$ 70,914
Financial Servcices Data-Driven Marketing [Member] | Nonrecurring [Member]
Schedule of asset impairment analyses [Line Items]
Excess of fair value over carrying value of reporting unit's net assets						$ 105,000								$ 105,000
Excess of fair value over carrying value of reporting unit, percentage						36.00%								36.00%
Goodwill impairment charge						$ 0
Small Business Services Web Services [Member]
Schedule of asset impairment analyses [Line Items]
Excess of fair value over carrying value of reporting unit's net assets																		$ 63,000
Excess of fair value over carrying value of reporting unit, percentage																		22.00%
Goodwill impairment charge			242,267
Goodwill																		$ 225,383
Small Business Services Web Services [Member] | Nonrecurring [Member] | Trade names [Member] | Reportable business segments [Member] | Small Business Services [Member]
Schedule of asset impairment analyses [Line Items]
Asset impairment charges			14,441
Small Business Services Web Services [Member] | Nonrecurring [Member] | Customer lists/relationships [Member] | Reportable business segments [Member] | Small Business Services [Member]
Schedule of asset impairment analyses [Line Items]
Asset impairment charges			11,655
Small Business Services Web Services [Member] | Nonrecurring [Member] | Technology-based intangibles [Member] | Reportable business segments [Member] | Small Business Services [Member]
Schedule of asset impairment analyses [Line Items]
Asset impairment charges			5,220
Small Business Services Indirect [Member]
Schedule of asset impairment analyses [Line Items]
Goodwill impairment charge							$ 78,188
Small Business Services Indirect [Member] | Trade names [Member] | Nonrecurring [Member] | Reportable business segments [Member] | Small Business Services [Member]
Schedule of asset impairment analyses [Line Items]
Asset impairment charges							$ 19,100
Fair value as of measurement date																		0
Small Business Services Indirect [Member] | Trade names [Member] | Significant unobservable inputs (Level 3) [Member] | Nonrecurring [Member] | Reportable business segments [Member] | Small Business Services [Member]
Schedule of asset impairment analyses [Line Items]
Fair value as of measurement date																		$ 0
Small Business Services Safeguard [Member]
Schedule of asset impairment analyses [Line Items]
Goodwill impairment charge											28,379
Intangible assets [Member] | Nonrecurring [Member] | Reportable business segments [Member] | Small Business Services [Member]
Schedule of asset impairment analyses [Line Items]
Asset impairment charges											3,499
Fair value as of measurement date											0
Intangible assets [Member] | Significant unobservable inputs (Level 3) [Member] | Nonrecurring [Member] | Reportable business segments [Member] | Small Business Services [Member]
Schedule of asset impairment analyses [Line Items]
Fair value as of measurement date											$ 0
Intangible assets [Member] | Small Business Services Web Services [Member] | Nonrecurring [Member] | Reportable business segments [Member] | Small Business Services [Member]
Schedule of asset impairment analyses [Line Items]
Asset impairment charges			$ 31,316
Assets held for sale [Member] | Nonrecurring [Member] | Reportable business segments [Member] | Small Business Services [Member]
Schedule of asset impairment analyses [Line Items]
Impairment charges, assets held for sale												8,250
Fair value as of measurement date												3,500
Assets held for sale [Member] | Significant unobservable inputs (Level 3) [Member] | Nonrecurring [Member] | Reportable business segments [Member] | Small Business Services [Member]
Schedule of asset impairment analyses [Line Items]
Fair value as of measurement date												$ 3,500

[1] The impairment charge consisted of $14,441 related to trade names, $11,655 related to customer lists and $5,220 related to technology-based intangible assets.

[2] The fair value presented is for the entire asset group that includes the impaired assets.