Segment and Geographic Area Information Geographic Area Information (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating revenues	$ 1,639,012	$ 1,568,643	$ 874,916
Percent of total operating revenues	100.00%	100.00%	100.00%
Property and equipment, net	3,788,482	3,440,744
Percent of total property and equipment	100.00%	100.00%
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating revenues	1,188,172	1,100,334	505,778
Percent of total operating revenues	72.50%	70.20%	57.80%
Property and equipment, net	3,003,299	2,642,263
Percent of total property and equipment	79.30%	76.80%
Australia [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating revenues	313,182	324,796	289,023
Percent of total operating revenues	19.10%	20.70%	33.00%
Property and equipment, net	506,154	557,292
Percent of total property and equipment	13.40%	16.20%
Canada [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating revenues	116,677	128,838	65,327
Percent of total operating revenues	7.10%	8.20%	7.50%
Property and equipment, net	266,305	226,310
Percent of total property and equipment	7.00%	6.60%
Europe [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating revenues	20,981	14,675	14,788
Percent of total operating revenues	1.30%	0.90%	1.70%
Property and equipment, net	12,724	14,879
Percent of total property and equipment	0.30%	0.40%
Total Non-United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating revenues	450,840	468,309	369,138
Percent of total operating revenues	27.50%	29.80%	42.20%
Property and equipment, net	$ 785,183	$ 798,481
Percent of total property and equipment	20.70%	23.20%