XML 56 R41.htm IDEA: XBRL DOCUMENT v3.6.0.2
Stock Plans (Tables)
 12 Months Ended
Dec. 31, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]  
Disclosure of Share-based Compensation Arrangements by Share-based Payment Award [Table Text Block]
Summary stock options activity is presented in the table below:
 
 
 
 
 
Number of
Shares
 
 
Weighted
Average
Exercise
Price
 
Weighted
Average
Remaining
Contractual
Term (years)
 
 
Aggregate
Intrinsic
Value
(thousands)
Balance at December 31, 2015 (1,907,094 shares exercisable)
 
3,226,221

 
$
31.40

 
 
 
 
Granted
 
336,472

 
$
73.69

 
 
 
 
Exercised
 
(215,378
)
 
$
19.02

 
 
 
 
Forfeited/Canceled
 
(36,339
)
 
$
58.43

 
 
 
 
Balance at December 31, 2016
 
3,310,976

 
$
36.20

 
5.9
 
$
121,073

Exercisable at December 31, 2016
 
2,154,790

 
$
21.95

 
4.5
 
$
108,910

Vested and expected to vest at December 31, 2016
 
3,124,174

 
$
34.38

 
5.7
 
$
119,818
Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]
The following table provides the fair value of options granted under the SCP during 2016, 2015 and 2014, together with a description of the assumptions used to calculate the fair value using the Black-Scholes-Merton option-pricing model:
 
 
Year ended December 31,
 
 
2016
 
2015
 
2014
Volatility
 
33.3
%
 
32.7
%
 
32.8
%
Risk-free interest rate - weighted average
 
2.0
%
 
1.7
%
 
1.7
%
Risk-free interest rate - range
 
1.29% to 2.01%

 
1.71% to 1.75%

 
1.67% to 1.88%

Dividend yield
 
—
%
 
—
%
 
—
%
Assumed forfeitures
 
8.0
%
 
8.0
%
 
8.0
%
Expected lives
 
5.5 years

 
5.4 years

 
5.5 years

Weighted-average fair value (per share)
 
$
25.29

 
$
24.29

 
$
18.57
Schedule of Nonvested Restricted Stock Units Activity [Table Text Block]
Summary restricted stock activity is presented in the table below:
 
 
 
 
Number of
Shares
 
Weighted
Average Grant
Date Fair
Value Per Share
Nonvested at December 31, 2015
 
572,828

 
$
47.54

Granted
 
125,259

 
$
73.86

Vested
 
(190,511
)
 
$
32.09

Forfeited
 
(12,708
)
 
$
57.13

Nonvested at December 31, 2016
 
494,868

 
$
59.90
Schedule of Share-based Payment Award, Employee Stock Purchase Plan, Valuation Assumptions [Table Text Block]
The following table provides the weighted-average fair value of the ESPP stock purchase rights during the years ended December 31, 2016, 2015 and 2014 and the assumptions used to calculate the fair value using the Black-Scholes-Merton option-pricing model:

 
 
Year Ended December 31,
 
 
2016
 
2015
 
2014
Volatility - weighted average
 
36.3
%
 
30.6
%
 
32.6
%
Volatility - range
 
20.0% to 50.1%

 
25.9% to 41.9%

 
26.6% to 43.4%

Risk-free interest rate - weighted average
 
0.24
%
 
0.01
%
 
0.03
%
Risk-free interest rate - range
 
0.22% to 0.29%

 
0.00% to 0.03%

 
0.02% to 0.05%

Dividend yield
 
—
%
 
—
%
 
—
%
Expected lives
 
3 months

 
3 months

 
3 months

Weighted-average fair value (per share)
 
$
14.42

 
$
12.44

 
$
9.16