Income Taxes - Reconciliation of Income Tax Provision to Statutory Federal Tax Rate (Details)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Statutory federal tax rate	35.00%	35.00%	35.00%
State taxes, net of federal taxes	2.60%	0.70%	0.50%
Resolution of uncertain tax positions	(0.90%)	(0.90%)	(0.50%)
Tax rate differential for international jurisdictions and other international related tax items	(11.30%)	(15.00%)	(13.60%)
U.S. tax credits	(1.90%)	(3.80%)	(0.20%)
Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Percent	(2.30%)	0.70%	0.80%
Effective Income Tax Rate Reconciliation, Deduction, Qualified Production Activity, Percent	(1.80%)	(1.50%)	(1.30%)
International reorganization of acquired companies	0.00%	0.60%	0.30%
Permanent items	3.90%	3.80%	2.80%
Other	(0.20%)	0.40%	0.30%
Effective income tax rate	23.10%	20.00%	24.10%