Long-Term Debt (Tables)

6 Months Ended

Jun. 30, 2013

Debt Disclosure [Abstract]

Carrying Amount of Components of Long-term Debt

The following table summarizes our long-term debt as of the dates presented:

	As of
	June 30,		December 31,
	2013		2012
Revolving credit facility	$	67,000	$	—
Senior notes due 2016, net of discount (principal amount of $300,000)	—		294,759
Senior notes due 2019	300,000		300,000
Senior notes due 2020	775,000		—
	$	1,142,000	$	594,759