Recent Accounting Developments (Policies)	9 Months Ended
Sep. 30, 2017
Accounting Policies [Abstract]
Recent Accounting Developments	In January 2017, the Financial Accounting Standards Board (FASB) issued guidance on simplifying the test for goodwill impairment (ASU No. 2017-04, Simplifying the Test for Goodwill Impairment). Under the new standard, goodwill impairment would be measured as the amount by which a reporting unit's carrying value exceeds its fair value, but not in an amount in excess of the carrying value of goodwill. The new guidance eliminates the requirement to determine goodwill impairment by calculating the implied fair value of goodwill by hypothetically assigning the fair value of a reporting unit to all of its assets and liabilities as if that reporting unit had been acquired in a business combination. The new guidance is to be applied prospectively to impairment tests beginning January 1, 2020, with early adoption permitted. We are currently evaluating when we will adopt the new guidance. In May 2014, the FASB issued guidance on the recognition of revenue from contracts with customers (ASU No. 2014-09, Revenue from Contracts with Customers). Revenue recognition will depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The guidance also requires disclosures regarding the nature, amount, timing and uncertainty of revenue and cash flows arising from contracts with customers. The guidance permits two methods of adoption: retrospectively to each prior reporting period presented or retrospectively with the cumulative effect of initially applying the guidance recognized on the date of adoption. The FASB has delayed the effective date of the standard by one year to January 1, 2018, with early adoption permitted as of the original effective date of January 1, 2017. We have performed a review of the requirements of the new guidance and have identified which of our revenue streams will be within the scope of ASU 2014-09. We have applied the five-step model of the new standard to a selection of contracts within each of our revenue streams, and have compared the results to our current accounting practices. Based on this analysis, we do not currently expect a material impact on our consolidated financial statements. We are continuing to evaluate the impact of the new guidance on our consolidated financial statements, and we anticipate that we will expand our consolidated financial statement disclosures in order to comply with the new ASU. As part of this, we are assessing changes that might be necessary to information technology systems, processes, and internal controls to capture new data and address changes in financial reporting. We now anticipate that we will adopt the new standard retrospectively, with recognition of a cumulative effect adjustment on January 1, 2018, the date of adoption. In February 2016, the FASB issued new lease accounting guidance (ASU No. 2016-02, Leases). Under the new guidance, at the commencement date, lessees will be required (a) to recognize a lease liability, which is a lessee's obligation to make lease payments arising from a lease, measured on a discounted basis, and (b) to record a right-of-use asset, which is an asset that represents the lessee’s right to use, or control the use of, a specified asset for the lease term. The new guidance is not applicable for leases with a term of 12 months or less. Lessor accounting is largely unchanged. U.S. public companies are required to apply the amendments in ASU 2016-02 for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. Early application is permitted. Lessees (for capital and operating leases) and lessors (for sales-type, direct financing, and operating leases) must apply a modified retrospective transition approach for leases existing at, or entered into after, the beginning of the earliest comparative period presented in the financial statements. The modified retrospective approach would not require any transition accounting for leases that expired before the earliest comparative period presented. Lessees and lessors may not apply a full retrospective transition approach. We are currently evaluating the impact of the new guidance on our consolidated financial statements. In July 2015, the FASB issued guidance that simplified the measurement of inventory (ASU No. 2015-11, Simplifying the Measurement of Inventory). The guidance requires an entity to measure inventory at the lower of cost or net realizable value, which consists of estimated selling prices in the ordinary course of business, less reasonably predictable costs of completion, disposal, and transportation. The new guidance eliminated unnecessary complexity that existed under previous "lower of cost or market" guidance. The updated guidance was applied prospectively beginning January 1, 2017. Our implementation of this standard did not have a material impact on our consolidated financial statements.

Recent Accounting Developments (Policies)

9 Months Ended

Sep. 30, 2017

In January 2017, the Financial Accounting Standards Board (FASB) issued guidance on simplifying the test for goodwill impairment (ASU No. 2017-04, Simplifying the Test for Goodwill Impairment). Under the new standard, goodwill impairment would be measured as the amount by which a reporting unit's carrying value exceeds its fair value, but not in an amount in excess of the carrying value of goodwill. The new guidance eliminates the requirement to determine goodwill impairment by calculating the implied fair value of goodwill by hypothetically assigning the fair value of a reporting unit to all of its assets and liabilities as if that reporting unit had been acquired in a business combination. The new guidance is to be applied prospectively to impairment tests beginning January 1, 2020, with early adoption permitted. We are currently evaluating when we will adopt the new guidance.

In May 2014, the FASB issued guidance on the recognition of revenue from contracts with customers (ASU No. 2014-09, Revenue from Contracts with Customers). Revenue recognition will depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The guidance also requires disclosures regarding the nature, amount, timing and uncertainty of revenue and cash flows arising from contracts with customers. The guidance permits two methods of adoption: retrospectively to each prior reporting period presented or retrospectively with the cumulative effect of initially applying the guidance recognized on the date of adoption. The FASB has delayed the effective date of the standard by one year to January 1, 2018, with early adoption permitted as of the original effective date of January 1, 2017. We have performed a review of the requirements of the new guidance and have identified which of our revenue streams will be within the scope of ASU 2014-09. We have applied the five-step model of the new standard to a selection of contracts within each of our revenue streams, and have compared the results to our current accounting practices. Based on this analysis, we do not currently expect a material impact on our consolidated financial statements. We are continuing to evaluate the impact of the new guidance on our consolidated financial statements, and we anticipate that we will expand our consolidated financial statement disclosures in order to comply with the new ASU. As part of this, we are assessing changes that might be necessary to information technology systems, processes, and internal controls to capture new data and address changes in financial reporting. We now anticipate that we will adopt the new standard retrospectively, with recognition of a cumulative effect adjustment on January 1, 2018, the date of adoption.

In February 2016, the FASB issued new lease accounting guidance (ASU No. 2016-02, Leases). Under the new guidance, at the commencement date, lessees will be required (a) to recognize a lease liability, which is a lessee's obligation to make lease payments arising from a lease, measured on a discounted basis, and (b) to record a right-of-use asset, which is an asset that represents the lessee’s right to use, or control the use of, a specified asset for the lease term. The new guidance is not applicable for leases with a term of 12 months or less. Lessor accounting is largely unchanged. U.S. public companies are required to apply the amendments in ASU 2016-02 for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. Early application is permitted. Lessees (for capital and operating leases) and lessors (for sales-type, direct financing, and operating leases) must apply a modified retrospective transition approach for leases existing at, or entered into after, the beginning of the earliest comparative period presented in the financial statements. The modified retrospective approach would not require any transition accounting for leases that expired before the earliest comparative period presented. Lessees and lessors may not apply a full retrospective transition approach. We are currently evaluating the impact of the new guidance on our consolidated financial statements.

In July 2015, the FASB issued guidance that simplified the measurement of inventory (ASU No. 2015-11, Simplifying the Measurement of Inventory). The guidance requires an entity to measure inventory at the lower of cost or net realizable value, which consists of estimated selling prices in the ordinary course of business, less reasonably predictable costs of completion, disposal, and transportation. The new guidance eliminated unnecessary complexity that existed under previous "lower of cost or market" guidance. The updated guidance was applied prospectively beginning January 1, 2017. Our implementation of this standard did not have a material impact on our consolidated financial statements.