Basis of Presentation (Policies)	3 Months Ended
Mar. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of presentation	Basis of Presentation The unaudited condensed consolidated financial statements have been prepared pursuant to the rules and regulations of the U.S. Securities and Exchange Commission (“SEC”) that permit reduced disclosure for interim periods. The condensed consolidated balance sheet as of December 31, 2017 was derived from audited financial statements, but does not include all necessary disclosures required by accounting principles generally accepted in the United States of America (“GAAP”). The unaudited condensed consolidated financial statements include all accounts of the Company and its subsidiaries and, in the opinion of management, include all recurring adjustments and normal accruals necessary for a fair statement of the Company’s financial position, results of operations and cash flows for the dates and periods presented. These unaudited financial statements should be read in conjunction with the Company’s Annual Report on Form 10-K for the year ended December 31, 2017 (“2017 Annual Report on Form 10-K”). Results for interim periods are not necessarily indicative of the results to be expected during the remainder of the current year or for any future period. All material intercompany accounts and transactions have been eliminated in consolidation.
Reclassifications	Reclassifications Certain prior year amounts have been reclassified to conform to the current year presentation.
Comprehensive income	Comprehensive income Comprehensive income is equal to the net income for all periods presented.
Recently issued accounting pronouncements	Recently adopted accounting pronouncements In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update 2014-09, Revenue from Contracts with Customers, and issued subsequent amendments to the initial guidance to provide additional clarification on specific topics (“Topic 606”). Topic 606 provides a comprehensive revenue recognition model requiring companies to recognize revenue for the transfer of goods or services to a customer at an amount that reflects the consideration it expects to receive in exchange for those goods or services. The guidance also requires additional disclosure about the nature, amount, timing and uncertainty of revenue and cash flows arising from customer contracts. The Company adopted Topic 606 on January 1, 2018 using the modified retrospective transition method. See Note 6 for further details. In August 2016, the FASB issued Accounting Standards Update 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments (“ASU 2016-15”). ASU 2016-15 was issued to decrease the diversity in practice of how certain cash receipts and cash payments are presented and classified in the statement of cash flows by providing guidance on eight specific cash flow issues. Retrospective application is required. ASU 2016-15 became effective for the Company’s annual and interim periods beginning on January 1, 2018. The adoption of the standard did not have an impact on the Company’s current or historical financial statements. In November 2016, the FASB issued Accounting Standards Update 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash (“ASU 2016-18”). ASU 2016-18 requires that the statement of cash flows include restricted cash in the beginning and end-of-period total amounts shown and that the statement of cash flows explain the changes in restricted cash during the period. Retrospective application is required. ASU 2016-18 became effective for the Company's annual and interim periods beginning on January 1, 2018. The adoption of the standard did not have an impact on the Company’s current or historical financial statements. In January 2017, the FASB issued Accounting Standards Update 2017-01, Business Combinations (Topic 805): Clarifying the Definition of a Business (“ASU 2017-01”). ASU 2017-01 provides guidance in determining when a set of assets and activities meets the definition of a business. Prospective application is required. ASU 2017-01 became effective for the Company's annual and interim periods beginning on January 1, 2018. The adoption of the standard did not have an impact on the Company’s current financial statements. In February 2017, the FASB issued Accounting Standards Update 2017-05, Other Income - Gains and Losses from the Derecognition of Nonfinancial Assets (Subtopic 610-20): Clarifying the Scope of Asset Derecognition Guidance and Accounting for Partial Sales of Nonfinancial Assets (“ASU 2017-05”). ASU 2017-05 clarifies the scope of Subtopic 610-20, which provides guidance for recognizing gains and losses from the sale or transfer of nonfinancial assets in contracts with noncustomers. ASU 2017-05 also provides guidance for partial sales of nonfinancial assets. ASU 2017-05 became effective for the Company’s annual and interim periods beginning on January 1, 2018. The adoption of the standard did not have an impact on the Company’s current or historical financial statements. In May 2017, the FASB issued Accounting Standards Update 2017-09, Compensation - Stock Compensation (Topic 718): Scope of Modification Accounting (“ASU 2017-09”). ASU 2017-09 provides guidance about which changes to the terms or conditions of a share-based payment award require an entity to apply modification accounting under Accounting Standards Codification (“ASC”) 718. ASU 2017-09 is to be applied prospectively to an award modified on or after the adoption date. ASU 2017-09 became effective for the Company’s annual and interim periods beginning on January 1, 2018. The adoption of the standard did not have an impact on the Company’s current financial statements. In March 2018, the FASB issued Accounting Standards Update 2018-05, Income Taxes (Topic 740): Amendments to SEC Paragraphs Pursuant to SEC Staff Accounting Bulletin No. 118 (“ASU 2018-05”). ASU 2018-05 adds paragraphs to the codification pursuant to SEC Staff Accounting Bulletin No. 118, which addresses the application of GAAP in situations when a company does not have the necessary information available, prepared or analyzed (including computations) in reasonable detail to complete the accounting for certain income tax effects of the Tax Cuts and Jobs Act (the “2017 Tax Act”). ASU 2018-05 provides entities with a one year measurement period from the December 22, 2017 enactment date in order to complete the accounting. The Company recognized a provisional net tax benefit of $3.6 million related to the impact of the 2017 Tax Act during the year ended December 31, 2017. The Company may record additional provisional amounts or adjustments to provisional amounts during the measurement period. Recently issued accounting pronouncements not yet adopted In February 2016, the FASB issued Accounting Standards Update 2016-02, Leases (“ASU 2016-02”). ASU 2016-02 establishes a right-of-use (“ROU”) model that requires a lessee to record a ROU asset and a lease liability on the balance sheet for all leases with terms longer than 12 months. Leases will be classified as either finance or operating, with classification affecting the pattern of expense recognition in the income statement. ASU 2016-02 is effective for the Company’s annual and interim periods beginning on January 1, 2019. A modified retrospective transition approach is required for lessees for capital and operating leases existing at, or entered into after, the beginning of the earliest comparative period presented in the financial statements, with certain practical expedients available. The Company is in the process of evaluating the impact of the standard on the Company’s financial statements. As a lessee, certain of the Company’s various leases under existing guidance are classified as operating leases that are not recorded on the balance sheet but are recorded in the statement of operations as expense is incurred. Upon adoption of the standard, the Company will be required to record substantially all leases on the balance sheet as a ROU asset and a lease liability. The timing of expense recognition and classification in the statement of operations could change based on the classification of leases as either operating or financing. In January 2017, the FASB issued Accounting Standards Update 2017-04, Intangibles - Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment (“ASU 2017-04”). ASU 2017-04 simplifies the accounting for goodwill impairment by removing Step 2 of the goodwill impairment test, which requires computation of the implied fair value of a reporting unit's goodwill. The amount of a goodwill impairment will now be the amount by which a reporting unit's carrying value exceeds its fair value, not to exceed the carrying amount of goodwill. ASU 2017-04 is effective for the Company's annual goodwill impairment test and any interim tests during the Company's annual and interim periods beginning on January 1, 2020. Early adoption is permitted for goodwill impairment tests performed on testing dates after January 1, 2017. Prospective application is required. The adoption of the standard is not expected to have a material impact on the Company’s financial statements.

Recently adopted accounting pronouncements

In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update 2014-09, Revenue from Contracts with Customers, and issued subsequent amendments to the initial guidance to provide additional clarification on specific topics (“Topic 606”). Topic 606 provides a comprehensive revenue recognition model requiring companies to recognize revenue for the transfer of goods or services to a customer at an amount that reflects the consideration it expects to receive in exchange for those goods or services. The guidance also requires additional disclosure about the nature, amount, timing and uncertainty of revenue and cash flows arising from customer contracts. The Company adopted Topic 606 on January 1, 2018 using the modified retrospective transition method. See Note 6 for further details.

In August 2016, the FASB issued Accounting Standards Update 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments (“ASU 2016-15”). ASU 2016-15 was issued to decrease the diversity in practice of how certain cash receipts and cash payments are presented and classified in the statement of cash flows by providing guidance on eight specific cash flow issues. Retrospective application is required. ASU 2016-15 became effective for the Company’s annual and interim periods beginning on January 1, 2018. The adoption of the standard did not have an impact on the Company’s current or historical financial statements.

In November 2016, the FASB issued Accounting Standards Update 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash (“ASU 2016-18”). ASU 2016-18 requires that the statement of cash flows include restricted cash in the beginning and end-of-period total amounts shown and that the statement of cash flows explain the changes in restricted cash during the period. Retrospective application is required. ASU 2016-18 became effective for the Company's annual and interim periods beginning on January 1, 2018. The adoption of the standard did not have an impact on the Company’s current or historical financial statements.

In January 2017, the FASB issued Accounting Standards Update 2017-01, Business Combinations (Topic 805): Clarifying the Definition of a Business (“ASU 2017-01”). ASU 2017-01 provides guidance in determining when a set of assets and activities meets the definition of a business. Prospective application is required. ASU 2017-01 became effective for the Company's annual and interim periods beginning on January 1, 2018. The adoption of the standard did not have an impact on the Company’s current financial statements.

In February 2017, the FASB issued Accounting Standards Update 2017-05, Other Income - Gains and Losses from the Derecognition of Nonfinancial Assets (Subtopic 610-20): Clarifying the Scope of Asset Derecognition Guidance and Accounting for Partial Sales of Nonfinancial Assets (“ASU 2017-05”). ASU 2017-05 clarifies the scope of Subtopic 610-20, which provides guidance for recognizing gains and losses from the sale or transfer of nonfinancial assets in contracts with noncustomers. ASU 2017-05 also provides guidance for partial sales of nonfinancial assets. ASU 2017-05 became effective for the Company’s annual and interim periods beginning on January 1, 2018. The adoption of the standard did not have an impact on the Company’s current or historical financial statements.

In May 2017, the FASB issued Accounting Standards Update 2017-09, Compensation - Stock Compensation (Topic 718): Scope of Modification Accounting (“ASU 2017-09”). ASU 2017-09 provides guidance about which changes to the terms or conditions of a share-based payment award require an entity to apply modification accounting under Accounting Standards Codification (“ASC”) 718. ASU 2017-09 is to be applied prospectively to an award modified on or after the adoption date. ASU 2017-09 became effective for the Company’s annual and interim periods beginning on January 1, 2018. The adoption of the standard did not have an impact on the Company’s current financial statements.

In March 2018, the FASB issued Accounting Standards Update 2018-05, Income Taxes (Topic 740): Amendments to SEC Paragraphs Pursuant to SEC Staff Accounting Bulletin No. 118 (“ASU 2018-05”). ASU 2018-05 adds paragraphs to the codification pursuant to SEC Staff Accounting Bulletin No. 118, which addresses the application of GAAP in situations when a company does not have the necessary information available, prepared or analyzed (including computations) in reasonable detail to complete the accounting for certain income tax effects of the Tax Cuts and Jobs Act (the “2017 Tax Act”). ASU 2018-05 provides entities with a one year measurement period from the December 22, 2017 enactment date in order to complete the accounting. The Company recognized a provisional net tax benefit of $3.6 million related to the impact of the 2017 Tax Act during the year ended December 31, 2017. The Company may record additional provisional amounts or adjustments to provisional amounts during the measurement period.

Recently issued accounting pronouncements not yet adopted

In February 2016, the FASB issued Accounting Standards Update 2016-02, Leases (“ASU 2016-02”). ASU 2016-02 establishes a right-of-use (“ROU”) model that requires a lessee to record a ROU asset and a lease liability on the balance sheet for all leases with terms longer than 12 months. Leases will be classified as either finance or operating, with classification affecting the pattern of expense recognition in the income statement. ASU 2016-02 is effective for the Company’s annual and interim periods beginning on January 1, 2019. A modified retrospective transition approach is required for lessees for capital and operating leases existing at, or entered into after, the beginning of the earliest comparative period presented in the financial statements, with certain practical expedients available. The Company is in the process of evaluating the impact of the standard on the Company’s financial statements. As a lessee, certain of the Company’s various leases under existing guidance are classified as operating leases that are not recorded on the balance sheet but are recorded in the statement of operations as expense is incurred. Upon adoption of the standard, the Company will be required to record substantially all leases on the balance sheet as a ROU asset and a lease liability. The timing of expense recognition and classification in the statement of operations could change based on the classification of leases as either operating or financing.

In January 2017, the FASB issued Accounting Standards Update 2017-04, Intangibles - Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment (“ASU 2017-04”). ASU 2017-04 simplifies the accounting for goodwill impairment by removing Step 2 of the goodwill impairment test, which requires computation of the implied fair value of a reporting unit's goodwill. The amount of a goodwill impairment will now be the amount by which a reporting unit's carrying value exceeds its fair value, not to exceed the carrying amount of goodwill. ASU 2017-04 is effective for the Company's annual goodwill impairment test and any interim tests during the Company's annual and interim periods beginning on January 1, 2020. Early adoption is permitted for goodwill impairment tests performed on testing dates after January 1, 2017. Prospective application is required. The adoption of the standard is not expected to have a material impact on the Company’s financial statements.