Income Taxes	3 Months Ended
Mar. 31, 2018
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes Income tax expense for the three months ended March 31, 2018 was $102.1 million, representing an effective tax rate of 21.1%. The provision for income taxes includes a $22.6 million benefit resulting from a change in accounting method regarding the timing of tax deductions for software development-related expenses, partially offset by a $15.8 million net provision recorded in the current period representing adjustments to the initial estimated impact of the TCJA. The prior-year three-month provision for income taxes was $114.8 million, representing an effective tax rate of 29.4%.

Income Taxes

3 Months Ended

Mar. 31, 2018

Income tax expense for the three months ended March 31, 2018 was $102.1 million, representing an effective tax rate of 21.1%. The provision for income taxes includes a $22.6 million benefit resulting from a change in accounting method regarding the timing of tax deductions for software development-related expenses, partially offset by a $15.8 million net provision recorded in the current period representing adjustments to the initial estimated impact of the TCJA.

The prior-year three-month provision for income taxes was $114.8 million, representing an effective tax rate of 29.4%.