Fair Value Measurements Carrying Amounts and Fair Values (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Restricted cash	$ 68,900		$ 10,600
Current maturities of long-term debt	(112,500)		(150,000)
Long-term debt	(1,461,724)		(1,120,052)
Carrying Amount [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	199,644		280,596
Restricted cash	68,944	[1]	10,559	[1]
Current maturities of long-term debt	(112,500)		(150,000)
Long-term debt	(1,461,724)		(1,120,052)
Fair Value, Level 1 [Member] | Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	199,644		280,596
Restricted cash	68,944	[1]	10,559	[1]
Current maturities of long-term debt	0		0
Long-term debt	0		0
Fair Value, Level 2 [Member] | Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	0		0
Restricted cash	0	[1]	0	[1]
Current maturities of long-term debt	(119,614)		(150,000)
Long-term debt	(1,489,810)		(1,250,341)
Fair Value, Measurements, Recurring [Member] | Carrying Amount [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate swaps	(4,659)	[2]	0	[2]
Fair Value, Measurements, Recurring [Member] | Carrying Amount [Member] | Foreign currency exchange contracts [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Foreign currency contract	940	[2]	0	[2]
Fair Value, Measurements, Recurring [Member] | Carrying Amount [Member] | Foreign currency option contracts [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Foreign currency contract	467	[2]	0	[2]
Fair Value, Measurements, Recurring [Member] | Carrying Amount [Member] | Fuel contracts [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fuel hedge contracts	160	[2]	0	[2]
Fair Value, Measurements, Recurring [Member] | Fair Value, Level 1 [Member] | Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate swaps	0	[2]	0	[2]
Fair Value, Measurements, Recurring [Member] | Fair Value, Level 1 [Member] | Fair Value [Member] | Foreign currency exchange contracts [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Foreign currency contract	0	[2]	0	[2]
Fair Value, Measurements, Recurring [Member] | Fair Value, Level 1 [Member] | Fair Value [Member] | Foreign currency option contracts [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Foreign currency contract	0	[2]	0	[2]
Fair Value, Measurements, Recurring [Member] | Fair Value, Level 1 [Member] | Fair Value [Member] | Fuel contracts [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fuel hedge contracts	0	[2]	0	[2]
Fair Value, Measurements, Recurring [Member] | Fair Value, Level 2 [Member] | Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate swaps	(4,659)	[2]	0	[2]
Fair Value, Measurements, Recurring [Member] | Fair Value, Level 2 [Member] | Fair Value [Member] | Foreign currency exchange contracts [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Foreign currency contract	940	[2]	0	[2]
Fair Value, Measurements, Recurring [Member] | Fair Value, Level 2 [Member] | Fair Value [Member] | Foreign currency option contracts [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Foreign currency contract	467	[2]	0	[2]
Fair Value, Measurements, Recurring [Member] | Fair Value, Level 2 [Member] | Fair Value [Member] | Fuel contracts [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fuel hedge contracts	$ 160	[2]	$ 0	[2]

[1] Restricted cash is recorded in “Other Assets” and represents the proceeds from LKE sales deposited with a third-party intermediary.

[2] See Note 6 — Derivative Financial Instruments and Hedging Activities for information regarding the Balance Sheet classification of the Company’s derivative financial instruments.