Fair Value	3 Months Ended
Mar. 31, 2014
Fair Value [Abstract]
Fair Value	Fair Value. We use a three-tier fair value hierarchy, which classifies the inputs used in measuring fair values, in determining the fair value of our non-financial assets and non-financial liabilities, which consist primarily of goodwill. These tiers include: Level 1, defined as observable inputs such as quoted prices for identical instruments in active markets; Level 2, defined as inputs other than quoted prices in active markets that are either directly or indirectly observable; and Level 3, defined as unobservable inputs in which little or no market data exists, therefore requiring an entity to develop its own assumptions. There were no changes in the methods and assumptions used in measuring fair value during the period. At March 31, 2014, our financial instruments include cash and cash equivalents, receivables, payables, senior debt and senior notes. The carrying amount of cash and cash equivalents, receivables and payables approximates fair value at March 31, 2014, and December 31, 2013, because of the short maturities of these instruments. Our senior debt is variable rate debt that re-prices frequently and entails no significant change in credit risk and, as a result, fair value approximates carrying value. The fair value of our senior notes is based on Level 1 inputs. At March 31, 2014, the fair value of our 6.625% senior notes was $310.5 million, which was approximately $10.5 million above their carrying value of $300.0 million. At December 31, 2013, the fair value of our 6.625% senior notes was $316.7 million, which was approximately $16.7 million above their carrying value of $300.0 million. At March 31, 2014, the fair value of our 4.75% senior notes was $233.4 million, which was approximately $16.6 million below their carrying value of $250.0 million.

Fair Value

3 Months Ended

Mar. 31, 2014

Fair Value.

We use a three-tier fair value hierarchy, which classifies the inputs used in measuring fair values, in determining the fair value of our non-financial assets and non-financial liabilities, which consist primarily of goodwill. These tiers include: Level 1, defined as observable inputs such as quoted prices for identical instruments in active markets; Level 2, defined as inputs other than quoted prices in active markets that are either directly or indirectly observable; and Level 3, defined as unobservable inputs in which little or no market data exists, therefore requiring an entity to develop its own assumptions. There were no changes in the methods and assumptions used in measuring fair value during the period.

At March 31, 2014, our financial instruments include cash and cash equivalents, receivables, payables, senior debt and senior notes. The carrying amount of cash and cash equivalents, receivables and payables approximates fair value at March 31, 2014, and December 31, 2013, because of the short maturities of these instruments. Our senior debt is variable rate debt that re-prices frequently and entails no significant change in credit risk and, as a result, fair value approximates carrying value. The fair value of our senior notes is based on Level 1 inputs. At March 31, 2014, the fair value of our 6.625% senior notes was $310.5 million, which was approximately $10.5 million above their carrying value of $300.0 million. At December 31, 2013, the fair value of our 6.625% senior notes was $316.7 million, which was approximately $16.7 million above their carrying value of $300.0 million. At March 31, 2014, the fair value of our 4.75% senior notes was $233.4 million, which was approximately $16.6 million below their carrying value of $250.0 million.