Income Taxes - Reconciliation of the Federal statutory income tax rate to the Companys effective tax rate (Details)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Tax Disclosure [Abstract]
Statutory Federal income tax rate	35.00%	35.00%	35.00%
State income taxes — net of Federal tax benefit	2.80%	4.20%	0.70%
Foreign tax rate differential	0.20%	0.50%	0.40%
Domestic production deduction	(3.20%)	(2.90%)	(3.50%)
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Other	1.50%	1.50%	2.00%
Changes in unrecognized tax benefits	0.40%	(1.60%)	(14.40%)
Non-deductible goodwill	0.00%	0.00%	3.10%
Foreign tax incentives	(2.20%)	(1.20%)	0.00%
Valuation allowances	(0.10%)	1.20%	3.00%
Other	(0.40%)	0.00%	1.00%
Effective tax rate for the year	34.00%	36.70%	27.30%