Segement Information Segment Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Segment Reporting Information [Line Items]
Revenues	$ 2,260,863	$ 1,963,832
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest	49,213	39,248
Income Tax Expense (Benefit)	(17,910)	(17,130)
Net Income (Loss) Attributable to Parent	31,303	22,118
U.S. [Member]
Segment Reporting Information [Line Items]
Revenues	1,834,626	1,721,787
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest	45,862	38,553
Income Tax Expense (Benefit)	(16,828)	17,089
Net Income (Loss) Attributable to Parent	29,034	21,464
U.K. [Member]
Segment Reporting Information [Line Items]
Revenues	247,701	171,078
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest	4,617	2,004
Income Tax Expense (Benefit)	(965)	488
Net Income (Loss) Attributable to Parent	3,652	1,516
Brazil [Member]
Segment Reporting Information [Line Items]
Revenues	178,536	70,967
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest	(1,266)	(1,309)
Income Tax Expense (Benefit)	(117)	(447)
Net Income (Loss) Attributable to Parent	$ (1,383)	$ (862)