Income Taxes (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Income Tax Disclosure [Abstract]
Effective tax rate	38.00%	36.30%	38.00%	37.80%
Cash paid for income taxes			$ 99,400,000	$ 142,500,000
Accrued liability for penalties	$ 500,000		500,000
Accrued liability for interest related to uncertain tax positions and penalties	10,900,000		10,900,000
Unrecognized tax benefits settlements with taxing authorities, minimum			0
Unrecognized tax benefits settlements with taxing authorities, maximum			10,000,000
Valuation allowance, state loss carryforwards	$ 61,000,000		$ 61,000,000