Employee Benefit Plans - Schedule of Stock Options Reserved for Future Issuance (Detail) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Stock options granted and outstanding	5.9	7.4
Unvested RSUs	3.6	3.0
Reserved for future grant	0.5	0.5
Employee Stock Purchase Plan	2.6	2.1
Total	12.6	13.0