Segment Information Geographic Area (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating revenues	$ 397,030	$ 376,279
Percent of operating revenue by geographic area	100.00%	100.00%
Property & equipment, net	4,014,856		3,788,482
Percent of property and equipment by geographic area	100.00%		100.00%
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating revenues	290,419	267,772
Percent of operating revenue by geographic area	73.10%	71.20%
Property & equipment, net	3,050,803		3,003,299
Percent of property and equipment by geographic area	76.00%		79.30%
Australia [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating revenues	59,941	76,292
Percent of operating revenue by geographic area	15.10%	20.30%
Property & equipment, net	469,409		506,154
Percent of property and equipment by geographic area	11.70%		13.40%
Canada [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating revenues	27,205	27,870
Percent of operating revenue by geographic area	6.90%	7.40%
Property & equipment, net	246,018		266,305
Percent of property and equipment by geographic area	6.10%		7.00%
Europe [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating revenues	19,465	4,345
Percent of operating revenue by geographic area	4.90%	1.20%
Property & equipment, net	248,626		12,724
Percent of property and equipment by geographic area	6.20%		0.30%
Total Non-United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating revenues	106,611	108,507
Percent of operating revenue by geographic area	26.90%	28.80%
Property & equipment, net	$ 964,053		$ 785,183
Percent of property and equipment by geographic area	24.00%		20.70%