Income Taxes - Items Accounting for Differences between Income Taxes Computed at Federal Statutory Rate and Provision Recorded for Income Taxes (Details)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Tax Disclosure [Abstract]
Federal statutory rate	35.00%	35.00%	35.00%
Effect of:
Impact of foreign tax differential	(8.10%)	31.50%	(8.40%)
State taxes, net of federal benefits	2.70%	0.20%	1.50%
Tax credits	(16.60%)	(4.40%)	(3.20%)
Nondeductible compensation	16.90%	13.30%	4.90%
Domestic production activities deduction	(2.10%)	0.00%	0.00%
Other, net	4.00%	3.00%	1.40%
Total	31.80%	78.60%	31.20%