Income Taxes (Narrative) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Income Tax Disclosure [Abstract]
Income tax expense	$ 39,105	$ 36,649
Effective tax rate	35.00%	37.00%
Federal statutory rate	35.00%	35.00%
State income tax expense	1,889	2,022
Undistributed Earnings of Foreign Subsidiaries	3,888
Effective Income Tax Rate Reconciliation, Deduction, Qualified Production Activity, Amount	2,777
Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense	3,334	1,060
Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Amount	647
Deferred Tax Assets, Tax Credit Carryforwards	1,017
Deferred Tax Assets, Tax Credit Carryforwards, Foreign	27,000
Adjustments to Additional Paid in Capital, Income Tax Benefit from Share-based Compensation	4,520
Second component of tax deductible goodwill, net of tax	$ 403