Stock-Based Compensation Option Activity (Detail) - USD ($) $ / shares in Units, shares in Millions, $ in Millions |
3 Months Ended | 6 Months Ended | 12 Months Ended | |||||||
|---|---|---|---|---|---|---|---|---|---|---|
Mar. 31, 2017 |
Dec. 31, 2016 |
Dec. 31, 2016 |
Dec. 31, 2015 |
Dec. 31, 2014 |
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| Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward] | ||||||||||
| Options outstanding, beginning of period (in shares) | 10.7 | 5.8 | 6.3 | 7.0 | ||||||
| Options granted (in shares) | 1.8 | 1.8 | 0.9 | 0.8 | ||||||
| Options exercised (in shares) | (0.3) | (1.6) | (1.2) | (1.3) | ||||||
| Options canceled/forfeited (in shares) | (0.1) | (0.8) | (0.2) | (0.2) | ||||||
| Aggregate impact of conversion related to the Separation (in shares) | [1] | 5.5 | ||||||||
| Options outstanding, end of period (in shares) | 12.1 | 10.7 | 10.7 | 5.8 | 6.3 | |||||
| Options vested and expected to vest (in shares) | [2] | 11.6 | 10.6 | 10.6 | ||||||
| Options vested (in shares) | 5.3 | 4.8 | 4.8 | |||||||
| Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract] | ||||||||||
| Options outstanding, beginning of period (in dollars per share) | $ 33.23 | $ 56.00 | $ 47.66 | $ 41.81 | ||||||
| Options granted (in dollars per share) | 57.26 | $ 51.84 | 87.96 | 77.63 | ||||||
| Options exercised (in dollars per share) | 25.35 | 26.13 | 35.28 | 33.78 | ||||||
| Options canceled/forfeited (in dollars per share) | 39.83 | 40.57 | 58.77 | 57.91 | ||||||
| Options outstanding, end of period (in dollars per share) | 36.86 | 33.23 | 33.23 | $ 56.00 | $ 47.66 | |||||
| Options vested and expected to vest (in dollars per share) | [2] | 36.40 | 32.40 | 32.40 | ||||||
| Options vested (in dollars per share) | $ 26.49 | $ 24.79 | $ 24.79 | |||||||
| Weighted average remaining contractual term, outstanding | 6 years 9 months 18 days | 6 years | ||||||||
| Weighted average remaining contractual term, vested and expected to vest | [2] | 6 years 8 months 12 days | 6 years | |||||||
| Weighted average remaining contractual term, vested | 4 years 9 months 18 days | 4 years | ||||||||
| Aggregate intrinsic value, outstanding | $ 282.3 | $ 218.1 | $ 218.1 | |||||||
| Aggregate intrinsic value, vested and expected to vest | [2] | 276.0 | 213.9 | 213.9 | ||||||
| Aggregate intrinsic value, vested | $ 180.4 | $ 139.3 | $ 139.3 | |||||||
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