Debt	6 Months Ended
Jun. 30, 2016
Debt Disclosure [Abstract]
Debt	Debt During the six months ended June 30, 2016, we made principal payments of $3.3 million on our seven-year term loan due October 2020. For the six months ended June 30, 2016 and 2015 cash payments for interest were $43.1 million and $42.9 million, respectively. Included in interest expense, net, are amortization of treasury lock settlements and amortization of financing costs. For both the three months ended June 30, 2016 and 2015 amortization of treasury lock settlements was $1.4 million, and for both the six months ended June 30, 2016 and 2015, amortization of treasury lock settlements was $2.8 million. For the three months ended June 30, 2016 and 2015 amortization of financing costs was $0.5 million and $0.4 million, respectively, and during the six months ended for both June 30, 2016 and 2015, amortization of financing costs was $0.9 million. For more information on our long-term debt and interest rates on that debt, see Note 10, Debt, of the Notes to Consolidated Financial Statements in "Part II, Item 8. Financial Statements and Supplementary Data" of our 2015 Annual Report on Form 10-K. At June 30, 2016 we had $1,650.0 million of fixed-rate senior notes and $658.8 million of variable-rate term loans outstanding. At June 30, 2016 the fair value of our fixed-rate debt was estimated to be $1,773.0 million. The difference between the book value and fair value is due to the difference between the period-end market interest rate and the stated rate of our fixed-rate debt. We estimated the fair value of our fixed-rate debt using quoted market prices (Level 2 inputs) within the fair value hierarchy, which is further defined in Note 2, Summary of Significant Accounting Policies, of the Notes to Consolidated Financial Statements in "Part II, Item 8. Financial Statements and Supplementary Data" of our 2015 Annual Report on Form 10-K. The fair value of our variable-rate term debt approximates the carrying amount as our cost of borrowing is variable and approximates current market rates.

Debt

During the six months ended June 30, 2016, we made principal payments of $3.3 million on our seven-year term loan due October 2020. For the six months ended June 30, 2016 and 2015 cash payments for interest were $43.1 million and $42.9 million, respectively.

Included in interest expense, net, are amortization of treasury lock settlements and amortization of financing costs. For both the three months ended June 30, 2016 and 2015 amortization of treasury lock settlements was $1.4 million, and for both the six months ended June 30, 2016 and 2015, amortization of treasury lock settlements was $2.8 million. For the three months ended June 30, 2016 and 2015 amortization of financing costs was $0.5 million and $0.4 million, respectively, and during the six months ended for both June 30, 2016 and 2015, amortization of financing costs was $0.9 million.

For more information on our long-term debt and interest rates on that debt, see Note 10, Debt, of the Notes to Consolidated Financial Statements in "Part II, Item 8. Financial Statements and Supplementary Data" of our 2015 Annual Report on Form 10-K.

At June 30, 2016 we had $1,650.0 million of fixed-rate senior notes and $658.8 million of variable-rate term loans outstanding. At June 30, 2016 the fair value of our fixed-rate debt was estimated to be $1,773.0 million. The difference between the book value and fair value is due to the difference between the period-end market interest rate and the stated rate of our fixed-rate debt. We estimated the fair value of our fixed-rate debt using quoted market prices (Level 2 inputs) within the fair value hierarchy, which is further defined in Note 2, Summary of Significant Accounting Policies, of the Notes to Consolidated Financial Statements in "Part II, Item 8. Financial Statements and Supplementary Data" of our 2015 Annual Report on Form 10-K. The fair value of our variable-rate term debt approximates the carrying amount as our cost of borrowing is variable and approximates current market rates.