Financing (Tables)

3 Months Ended

Mar. 31, 2016

Debt Disclosure [Abstract]

Outstanding financing facilities

	March 31, 2016		December 31, 2015
Revolving Credit Facility	$	—	$	—
$500 million, 4.875% Senior Notes due 2021(1), effective interest rate of 4.962%	496,153		495,951
$300 million, 4.625% Senior Notes due 2021(2), effective interest rate of 4.647%	298,466		298,396
$300 million, 3.800% Senior Notes due 2022(3), effective interest rate of 3.845%	297,617		297,535
$300 million, 3.850% Senior Notes due 2023(4), effective interest rate of 3.851%	298,190		298,136
$500 million, 3.550% Senior Notes due 2026(5), effective interest rate of 3.570%	495,451		—
Long-term debt	$	1,885,877	$	1,390,018

⁽¹⁾  Net of unamortized discount of $1.7 million as of March 31, 2016, and $1.8 million as of December 31, 2015, and debt issuance costs of $2.2 million as of March 31, 2016, and $2.3 million as of December 31, 2015.

⁽²⁾  Net of unamortized discount of $0.3 million as of March 31, 2016, and December 31, 2015, and debt issuance costs of $1.2 million as of March 31, 2016, and $1.3 million as of December 31, 2015.

⁽³⁾  Net of unamortized discount of $0.8 million as of March 31, 2016, and December 31, 2015, and debt issuance costs of $1.6 million as of March 31, 2016, and $1.7 million as of December 31, 2015.

⁽⁴⁾  Net of unamortized discount of less than $0.1 million as of March 31, 2016, and December 31, 2015, and debt issuance costs of $1.8 million as of March 31, 2016, and December 31, 2015.

⁽⁵⁾  Net of unamortized discount of $0.8 million as of March 31, 2016, and debt issuance costs of $3.7 million as of March 31, 2016.