Segment Information Revenue from External Customers, by Geographical Areas (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	$ 3,104,183	$ 3,082,646	$ 2,882,184
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	3,045,738	3,042,435	2,863,694
Mexico [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	47,169	22,603	4,303
Canada [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	$ 11,276	$ 17,608	$ 14,187