Stock Plans (Details) shares in Thousands	12 Months Ended
	Dec. 31, 2015 $ / shares shares
Summary of Stock Option and RSA Activity
Beginning Balance, Shares | shares	13,416
Granted, shares | shares	301
Exercised, shares | shares	(2,921)
Forfeited, shares | shares	(10)
Expired, shares | shares	34
Ending Balance, Shares | shares	10,820
Beginning balance, weighted average exercise price | $ / shares	$ 44.88
Granted, weighted average exercise price | $ / shares	83.3
Exercised, weighted average exercise price | $ / shares	49.96
Forfeitures, weighted average exercise price | $ / shares	49.22
Expired, weighted average exercise price | $ / shares	50.04
Ending balance, weighted average exercise price | $ / shares	$ 44.6
Options vested and expected to vest, shares | shares	10,820
Options vested and expected to vest, Weighted Average Exercise Price | $ / shares	$ 44.6
Options exercisable, shares | shares	9,809
Options exercisable, Weighted Average Exercise Price | $ / shares	$ 41.78
Beginning balance, shares | shares	7,874
Granted, shares | shares	3,069
Vested, shares | shares	(3,003)
Forfeited, shares | shares	(507)
Ending balance, shares | shares	7,433
Beginning Balance, Weighted Average Grant Price | $ / shares	$ 64.48
Granted, Weighted Average Grant Price | $ / shares	81.99
Vested, Weighted Average Grant Price | $ / shares	55.17
Forfeited, Weighted Average Grant Price | $ / shares	75.99
Ending Balance, Weighted Average Grant Price | $ / shares	$ 74.67