Income Taxes - Unrecognized Tax Benefits (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Tax Contingency [Line Items]
Significant change in unrecognized tax benefits is reasonably possible, estimated range of change, lower bound	$ 0
Significant change in unrecognized tax benefits is reasonably possible, estimated range of change, upper bound	27,000,000
Unrecognized tax benefits	77,089,000	78,440,000	176,089,000	189,041,000
Additions based on tax positions related to the current year	11,765,000	9,057,000	10,214,000
Additions for tax positions of prior years	1,564,000	10,899,000	7,598,000
Reductions for tax positions of prior years	(6,047,000)	(102,850,000)	(14,282,000)
Settlements	(998,000)	(5,346,000)	(503,000)
Lapse of statutes	(7,635,000)	(9,409,000)	(15,979,000)
Unrecognized potential tax benefits that would impact effective tax rate	48,800,000
Potential interest and penalty expense (income)	(1,300,000)	(5,500,000)	100,000
Accrued interest and penalties	15,500,000	17,100,000
Continuing Operations [Member]
Income Tax Contingency [Line Items]
Unrecognized tax benefits	66,367,000	65,226,000	121,864,000	134,773,000
Additions based on tax positions related to the current year	11,751,000	9,056,000	10,188,000
Additions for tax positions of prior years	1,065,000	7,584,000	4,128,000
Reductions for tax positions of prior years	(5,782,000)	(62,610,000)	(14,257,000)
Settlements	(843,000)	(2,823,000)	(418,000)
Lapse of statutes	(5,050,000)	(7,845,000)	(12,550,000)
Discontinued Operations [Member]
Income Tax Contingency [Line Items]
Unrecognized tax benefits	10,722,000	13,214,000	54,225,000	54,268,000
Additions based on tax positions related to the current year	14,000	1,000	26,000
Additions for tax positions of prior years	499,000	3,315,000	3,470,000
Reductions for tax positions of prior years	(265,000)	(40,240,000)	(25,000)
Settlements	(155,000)	(2,523,000)	(85,000)
Lapse of statutes	$ (2,585,000)	$ (1,564,000)	$ (3,429,000)