Annual report pursuant to Section 13 and 15(d)

Stock-Based Compensation and Employee Benefits Plan - Awards (Details)

v3.8.0.1
Stock-Based Compensation and Employee Benefits Plan - Awards (Details) - USD ($)
$ / shares in Units, shares in Thousands, $ in Millions
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Proceeds from Stock Options Exercised $ 7.9 $ 3.6 $ 8.2
Employee Service Share-based Compensation, Tax Benefit Realized from Exercise of Stock Options $ 11.9 $ 5.7 $ 6.1
Restricted Stock Unit and Restricted Stock Award [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding, Number 3,183 3,670  
Weighted-average grant date fair value per share $ 20.13 $ 14.67  
RSUs granted in period (shares) 1,514    
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value $ 27.11    
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Period Increase (Decrease) 250    
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period (1,763)    
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Intrinsic Value, Amount Per Share $ 16.21    
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period (488)    
Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures and Expirations in Period, Weighted Average Intrinsic Value $ 20.36    
Exar Corporation [Member] | Restricted Stock Unit and Restricted Stock Award [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value $ 31.12