Accounting Policies (Tables)

6 Months Ended

Jun. 30, 2017

Accounting Policies [Abstract]

Summary Of The Most Significant Impacts Of The New Accounting Guidance

Description of Change:	Impact of Change for the Three Months Ended March 31, 2017 and 2016 if applicable:	Adoption Method:
Tax benefits related to share-based payments at settlement are recorded through the income statement instead of equity	Decreases in income tax expense by approximately $7.1 million for the three months ended June 30, 2017, and approximately $18.3 million for the six months ended June 30, 2017	Prospective (required)
Calculation of diluted shares outstanding under the treasury method will no longer assume that tax benefits related to share-based payments are used to repurchase common stock	Increase in the weighted average diluted shares outstanding by approximately 450,000 shares for both the three and six months ended June 30, 2017	Prospective (required)
An election can be made to reduce share-based compensation expense for forfeitures as they occur instead of estimating forfeitures that are expected to occur	No change to share-based compensation expense, as we have elected to continue to estimate forfeitures that are expected to occur	N/A
Tax benefits related to share-based payments at settlement are classified as operating cash flows instead of financing cash flows	Increases in cash flow from operating activities and decreases in cash flow from financing activities by approximately $18.3 million for the six months ended June 30, 2017	Prospective (elected)
Cash payments to tax authorities for shares withheld to meet employee tax withholding requirements on restricted stock units are classified as financing cash flow instead of operating cash flow	Increases in cash flow from operating activities and decreases in cash flow from financing activities for the six months ended June 30, 2017 and 2016 by approximately $7.5 and $3.7 million, respectively	Retrospective (required)