Fair Value Measurements (Tables)

6 Months Ended

Jun. 30, 2015

Fair Value, Liabilities Measured on Recurring and Nonrecurring Basis [Table Text Block]

The carrying amounts and estimated fair values of our long-term debt at June 30, 2015 and December 31, 2014 were as follows:



	June 30, 2015				December 31, 2014
	Carrying Value		Estimated Fair Value		Carrying Value		Estimated Fair Value
	(in millions)
Senior long-term debt	$	387.2	$	377.8	$	132.0	$	132.0
Junior long-term debt	48.6		48.7		16.0		16.1
Total long-term debt	$	435.8	$	426.5	$	148.0	$	148.1

Schedule of assets and liabilities measured at fair value on a recurring basis

Assets and liabilities measured at gross fair value on a recurring basis are summarized below:



	Fair Value Measurements as of June 30, 2015
	Total		Level 1		Level 2		Level 3
	(in millions)
Cash and cash equivalents	$	769.3	$	769.3	$	—	$	—
Jet fuel options	1.5		—		—		1.5
Total assets	$	770.8	$	769.3	$	—	$	1.5

Interest rate swaps	$	1.7	$	—	$	1.7	$	—
Total liabilities	$	1.7	$	—	$	1.7	$	—



	Fair Value Measurements as of December 31, 2014
	Total		Level 1		Level 2		Level 3
	(in millions)
Cash and cash equivalents	$	632.8	$	632.8	$	—	$	—
Jet fuel options	4.8		—		—		4.8
Total assets	$	637.6	$	632.8	$	—	$	4.8

Interest rate swaps	$	1.1	$	—	$	1.1	$	—
Total liabilities	$	1.1	$	—	$	1.1	$	—

Schedule of assets and liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3)

The following tables present the Company's activity for assets and liabilities measured at gross fair value on a recurring basis using significant unobservable inputs (Level 3):



	Jet Fuel Option Activity for the Three Months Ended June 30, 2015
	(in millions)
Balance at March 31, 2015	$	2.5
Total realized or unrealized gains (losses) included in earnings, net	(0.6		)
Purchases	—
Sales	—
Settlements, net	(0.4		)
Balance at June 30, 2015	$	1.5



	Jet Fuel Option Activity for the Six Months Ended June 30, 2015
	(in millions)
Balance at December 31, 2014	$	4.8
Total realized or unrealized gains (losses) included in earnings, net	(4.9		)
Purchases	2.1
Sales	—
Settlements, net	(0.5		)
Balance at June 30, 2015	$	1.5