SEGMENT REPORTING - Financial Information Concerning Company's Reportable Segments (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Segment Reporting Information [Line Items]
Revenues	$ 882,774	$ 890,144	$ 2,692,906	$ 2,655,946
Gross Profit	368,039	375,956	1,118,453	1,120,177
Intangible amortization	29,905	33,128	88,475	102,311	$ 129,300
Adjusted EBITA	175,863	191,713	529,333	564,168
Domestic and Canada RCS
Segment Reporting Information [Line Items]
Revenues	634,682	631,668	1,917,521	1,878,451
Gross Profit	276,700	285,552	839,713	844,940
Intangible amortization	21,944	26,184	65,534	73,906
Adjusted EBITA	185,027	194,512	568,893	571,562
International Regulated and Compliance Services
Segment Reporting Information [Line Items]
Revenues	174,603	187,735	536,244	570,609
Gross Profit	54,965	57,002	169,955	178,633
Intangible amortization	5,917	4,982	16,846	22,484
Adjusted EBITA	15,644	17,942	54,045	53,588
All Other Segments
Segment Reporting Information [Line Items]
Revenues	73,489	70,741	239,141	206,886
Gross Profit	36,374	33,402	108,785	96,604
Intangible amortization	2,044	1,962	6,095	5,921
Adjusted EBITA	$ (24,808)	$ (20,741)	$ (93,605)	$ (60,982)