Recently Issued Accounting Standards - Narrative (Details)	12 Months Ended
	Dec. 31, 2017
Accounting Standards Update 201609 [Member]
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
New Accounting Pronouncement Or Change In Accounting Principle Description	The FASB issued an accounting standard update in March 2016 involving several aspects of the accounting for share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities, use of a forfeiture rate, and classification on the statement of cash flows. The guidance within this accounting standard update was effective for annual and interim periods beginning after December 15, 2016. When adopted, application of the guidance will vary based on each aspect of the update, including adoption under retrospective, modified retrospective or prospective approaches. Early adoption was permitted. During the first quarter of 2017, the Company adopted the guidance within the accounting standard update as required. The impact of adoption for the Company included the elimination of recording the tax effects of deductions in excess of compensation cost through equity as the guidance in this accounting standard update requires all tax effects related to share-based payments to now be recorded through the income statement. The tax effects of awards are required to be treated as discrete items in the interim reporting period in which the share-based compensation-related tax benefits occur. In addition, when applying the treasury stock method for computing diluted earnings per share, there are no longer assumed proceeds from the share-based compensation-related tax benefits and as a result, there are fewer shares considered to be repurchased in the calculation. This results in an assumption of more incremental shares being issued upon the exercise of share-based payment awards; therefore, equity awards will have a more dilutive effect on earnings per share. As required, the Company has applied these changes in the guidance prospectively, beginning in the first quarter of 2017. The result of these changes was a tax benefit of $1.4 million recorded during the year ended December 31, 2017 and an immaterial number of dilutive shares added to the Company’s earnings per share calculation for the year ended December 31, 2017. In addition, all tax-related cash flows resulting from share-based payments are now required to be reported as operating activities in the statement of cash flows under this new guidance. Either prospective or retrospective transition of this provision was permitted, and the Company has elected to apply the cash flow classification guidance on a prospective basis, consistent with the prospective transition for the treatment of excess tax benefits in the income statement. Lastly, the accounting standard update permitted Companies to make an accounting policy election to account for forfeitures as they occur for service condition aspects of certain share-based awards, rather than estimating forfeitures each period. While permitted, the Company has decided not to elect this accounting policy change, and instead has elected to continue utilizing a forfeiture rate assumption. Based on historical experience, the Company has assumed a forfeiture rate of 13% on certain of its nonvested stock awards.