PROPERTY AND EQUIPMENT, NET (Tables)

12 Months Ended

Dec. 31, 2017

Property and Equipment, Net

		December 31,
		2017		2016
Office and computer equipment (3 - 10 year estimated useful life)		$	219.5	$	189.1
Office furniture and fixtures (3 - 10 year estimated useful life)			50.5		47.1
Internal-use computer software (1 - 10 year estimated useful life)			520.3		452.1
Leasehold improvements and building (2 - 20 year estimated useful life)			240.8		233.1
	Total property and equipment, at cost		1,031.1		921.4
Less: accumulated depreciation and amortization			(706.0)		(595.5)
Total property and equipment, net		$	325.1	$	325.9