Income Taxes (Details 3)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Disclosure - Income Taxes - Additional Information [Abstract]
Statutory federal tax rate	35.00%	35.00%	35.00%
Foreign rate differential	(7.80%)	(12.70%)	(11.60%)
Foreign, federal and state income tax credits	(2.10%)	(1.70%)	(2.20%)
State taxes	2.40%	2.10%	1.00%
Non-deductible expenses	0.00%	0.00%	1.10%
Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Percent	(6.40%)	(0.10%)	0.00%
Other	(0.20%)	(2.90%)	(0.60%)
Effective tax rate	20.90%	19.70%	22.70%