Components of Deferred Tax Assets and Liabilities (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012		Dec. 31, 2011
Deferred tax assets:
Account receivable allowances	$ 8.2		$ 8.0
Accrued compensation and benefits	13.3		12.3
Legal and professional fees	8.4		9.8
Restructuring	1.5		1.4
Total current	40.6		84.3
Accumulated depreciation and amortization	0.4		1.3
Stock-based compensation	86.9		89.6
Benefit plans	96.6		82.7
Deferred rent and construction allowance	31.3		30.5
Foreign net operating loss	13.0	[1]	9.7	[1]
Self-insured related reserves	33.8		23.0
Total non-current	326.7		301.6
Total deferred tax assets	367.3		385.9
Deferred tax liabilities:
Accumulated depreciation and amortization of intangible assets and capitalized software	(154.7)		(161.3)
Foreign earnings to be repatriated	(4.7)		(2.6)
Self-insured related income	(39.7)		(26.8)
Total non-current	(203.0)		(193.1)
Total deferred tax liabilities	(203.2)		(193.1)
Net deferred tax asset	164.1		192.8
Valuation allowance	(15.2)		(13.9)
Total net deferred tax assets	148.9		178.9
Current
Deferred tax assets:
Deferred revenue	6.1		5.8
Uncertain tax positions			43.6
Other	3.1		3.4
Deferred tax liabilities:
Other liabilities	(0.2)
Total Current	(0.2)
Non-Current
Deferred tax assets:
Deferred revenue	34.3		36.4
Uncertain tax positions	25.9		21.2
Other	4.5		7.2
Deferred tax liabilities:
Other liabilities	$ (3.9)		$ (2.4)

[1] Amounts are primarily set to expire beginning in 2017, if unused.