Income Taxes	3 Months Ended
Mar. 31, 2018
Income Tax Disclosure [Abstract]
Income Taxes	12. Income Taxes The Company’s effective income tax rate fluctuates based on, among other factors, changes in statutory tax rates, changes in pretax income and nondeductible items, and changes in valuation allowances. The Company’s effective income tax rate for the three months ended March 31, 2018 was (0.8)%, compared with 36.8% for the three months ended March 31, 2017. The lower effective income tax rate for the three months ended March 31, 2018 was primarily attributable to the impact of the reduction to the U.S. federal statutory tax rate and additional limitations for the deductibility of meals and entertainment expenses as a result of Tax Reform. The Company also recorded a valuation allowance against the net deferred tax assets of a certain Canadian subsidiary of the Company due to a change in judgment as to the realizability of these assets. The Company recognized the income tax effects of Tax Reform in its audited financial statements included in the Company’s 2017 Annual Report on Form 10-K in accordance with Staff Accounting Bulletin No. 118, which provides SEC staff guidance for the application of ASC Topic 740, Income Taxes, in the reporting period during which Tax Reform was signed into law. The guidance also provides for a measurement period of up to one year from the enactment date of Tax Reform for the Company to complete its accounting for the U.S. tax law changes. As such, the Company’s 2017 financial results reflected the provisional estimate of the income tax effects of the Tax Reform. No subsequent adjustments have been made to the amounts recorded as of December 31, 2017, which continue to represent a provisional estimate of the impact of Tax Reform. The estimate of the impact of Tax Reform was based on certain assumptions and the Company’s current interpretation of Tax Reform. This estimate may change as the Company receives additional clarification and implementation guidance and as additional interpretations of Tax Reform become available.

12. Income Taxes

The Company’s effective income tax rate fluctuates based on, among other factors, changes in statutory tax rates, changes in pretax income and nondeductible items, and changes in valuation allowances.

The Company’s effective income tax rate for the three months ended March 31, 2018 was (0.8)%, compared with 36.8% for the three months ended March 31, 2017. The lower effective income tax rate for the three months ended March 31, 2018 was primarily attributable to the impact of the reduction to the U.S. federal statutory tax rate and additional limitations for the deductibility of meals and entertainment expenses as a result of Tax Reform. The Company also recorded a valuation allowance against the net deferred tax assets of a certain Canadian subsidiary of the Company due to a change in judgment as to the realizability of these assets.

The Company recognized the income tax effects of Tax Reform in its audited financial statements included in the Company’s 2017 Annual Report on Form 10-K in accordance with Staff Accounting Bulletin No. 118, which provides SEC staff guidance for the application of ASC Topic 740, Income Taxes, in the reporting period during which Tax Reform was signed into law. The guidance also provides for a measurement period of up to one year from the enactment date of Tax Reform for the Company to complete its accounting for the U.S. tax law changes. As such, the Company’s 2017 financial results reflected the provisional estimate of the income tax effects of the Tax Reform. No subsequent adjustments have been made to the amounts recorded as of December 31, 2017, which continue to represent a provisional estimate of the impact of Tax Reform. The estimate of the impact of Tax Reform was based on certain assumptions and the Company’s current interpretation of Tax Reform. This estimate may change as the Company receives additional clarification and implementation guidance and as additional interpretations of Tax Reform become available.