Income Taxes	9 Months Ended
Sep. 30, 2014
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes Income tax expense for each of the three months ended September 30, 2014 and 2013 was $7.1 million, or 36.3% of pre-tax income, and $6.5 million, or 38.1% of pre-tax income, respectively. Income tax expense for each of the nine months ended September 30, 2014 and 2013 was $17.6 million, or 34.3% of pre-tax income, and $14.5 million, or 32.8%, of pre-tax income, respectively. The Company’s estimated annual 2014 effective tax rate at September 30, 2014 is approximately 34.0%. This differs from the U.S. federal statutory rate of 35% due principally to items such as state and local income taxes, the federal domestic activities deduction and state income tax credits. The Company's income tax expense for the three months ended September 30, 2014 and 2013 had return to provision adjustments that caused the effective tax rate to be higher than expected. The Company's income tax expense for the nine months ended September 30, 2014 was decreased by $0.7 million due to a change in method of accounting for state investment credits to recognize them as each annual portion of the credit becomes available for use on tax returns. The income tax provision for the nine months ended September 30, 2013 reflected discrete benefits related to the Research and Development (“R&D”) Credit and the Indian Employment Credit. These federal credits were retroactively reinstated on January 2, 2013, with the enactment of the American Taxpayer Relief Act of 2012. The Company also had a change in estimate related to the recoverability of certain 2012 tax credits that was recorded in the first quarter of 2013, causing our effective tax rate to be reduced. This change in estimate was the result of additional and better information. We file income tax returns in the U.S., state and foreign income tax returns jurisdictions. We are subject to U.S. examinations for tax years 2011 to present, and to non-U.S. income tax examinations for the tax years of 2008 through 2011. In addition, we are subject to state and local income tax examinations for the tax years 2010 to present. In June 2014, the Internal Revenue Service ("IRS") notified the Company of its plans to examine the income tax returns for 2012. In October 2014, the IRS notified the Company of its plans to examine the income tax returns for 2013 and the State of Illinois notified the Company of its plans to examine the state state income tax returns for 2011 and 2012. We do not expect any significant assessment with respect to any current examinations. The Company continues to evaluate its need to file returns in various state jurisdictions. Any interest or penalties would be recognized as a component of income tax expense.

Income Taxes

Income tax expense for each of the three months ended September 30, 2014 and 2013 was $7.1 million, or 36.3% of pre-tax income, and $6.5 million, or 38.1% of pre-tax income, respectively. Income tax expense for each of the nine months ended September 30, 2014 and 2013 was $17.6 million, or 34.3% of pre-tax income, and $14.5 million, or 32.8%, of pre-tax income, respectively. The Company’s estimated annual 2014 effective tax rate at September 30, 2014 is approximately 34.0%. This differs from the U.S. federal statutory rate of 35% due principally to items such as state and local income taxes, the federal domestic activities deduction and state income tax credits. The Company's income tax expense for the three months ended September 30, 2014 and 2013 had return to provision adjustments that caused the effective tax rate to be higher than expected. The Company's income tax expense for the nine months ended September 30, 2014 was decreased by $0.7 million due to a change in method of accounting for state investment credits to recognize them as each annual portion of the credit becomes available for use on tax returns. The income tax provision for the nine months ended September 30, 2013 reflected discrete benefits related to the Research and Development (“R&D”) Credit and the Indian Employment Credit. These federal credits were retroactively reinstated on January 2, 2013, with the enactment of the American Taxpayer Relief Act of 2012. The Company also had a change in estimate related to the recoverability of certain 2012 tax credits that was recorded in the first quarter of 2013, causing our effective tax rate to be reduced. This change in estimate was the result of additional and better information.

We file income tax returns in the U.S., state and foreign income tax returns jurisdictions. We are subject to U.S. examinations for tax years 2011 to present, and to non-U.S. income tax examinations for the tax years of 2008 through 2011. In addition, we are subject to state and local income tax examinations for the tax years 2010 to present. In June 2014, the Internal Revenue Service ("IRS") notified the Company of its plans to examine the income tax returns for 2012. In October 2014, the IRS notified the Company of its plans to examine the income tax returns for 2013 and the State of Illinois notified the Company of its plans to examine the state state income tax returns for 2011 and 2012. We do not expect any significant assessment with respect to any current examinations. The Company continues to evaluate its need to file returns in various state jurisdictions. Any interest or penalties would be recognized as a component of income tax expense.