Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Deferred tax assets:
Contract liabilities	$ 40.7	$ 0.0
Equity compensation plans	21.1	17.7
Net operating loss and credit carryforwards, net	20.1	23.8
Payroll and benefits	9.6	9.3
Rent	7.3	7.5
Accounts receivable	7.0	6.5
Other	14.1	10.0
Total deferred tax assets	119.9	74.8
Deferred tax liabilities:
Acquisition-related intangibles	112.2	148.6
Property and equipment	27.0	20.0
International investments	19.2	19.2
Other	3.3	11.7
Total deferred tax liabilities	161.7	199.5
Deferred tax asset valuation allowance	16.8	17.2
Net deferred tax liabilities	$ 58.6	$ 141.9