Annual report pursuant to Section 13 and 15(d)

Stock-Based Compensation Expense - Restricted Shares (Details)

v3.8.0.1
Stock-Based Compensation Expense - Restricted Shares (Details) - USD ($)
$ / shares in Units, $ in Thousands
 12 Months Ended
Mar. 31, 2018
Mar. 31, 2017
Mar. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Issuance of restricted stock as deferred compensation to employees and directors   19,824  
Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Grants In Period, Value   $ 385  
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]      
Exercised (in shares)     (69,704)
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]      
Exercised, weighted average exercise price (in dollars per share)     $ 21.97
Restricted Stock Units (RSUs) [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Aggregate intrinsic value $ 5,134    
Total unrecognized expense related to non-vested stock option awards $ 2,841    
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]      
Outstanding, beginning of period (in shares) 208,146 192,221 198,822
Granted (in shares) 119,302 135,855 98,009
Exercised (in shares) (88,084) (111,611)  
Forfeited (in shares) (10,252) (8,319) (34,906)
Outstanding, end of period (in shares) 229,112 208,146 192,221
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]      
Options outstanding, weighted average grant price, beginning of period (in dollars per share) $ 20.64 $ 23.36 $ 22.38
Granted, weighted average exercise price (in dollars per share) 19.16 18.65 24.08
Exercised, weighted average exercise price (in dollars per share) 21.51 22.74  
Forfeited, weighted average exercise price (in dollars per share) 20.05 21.25 22.53
Options outstanding, weighted average grant price, end of period (in dollars per share) $ 19.55 $ 20.64 $ 23.36
Stock based compensation, recognition period 1 year 7 months 24 days    
Performance Shares [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, Value $ 1,420 $ 881 $ 1,113
Total unrecognized expense related to non-vested stock option awards $ 1,231    
Vested shares 0 0 31,658,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]      
Granted (in shares) 0 0 22,989,000
Forfeited (in shares) 0 0 (8,669,000)
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]      
Stock based compensation, recognition period 2 years 2 months 19 days    
Minimum [Member] | Performance Shares [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Share Based Compensation Arrangement, Possible Number Of Shares Issued Each Year 0 0  
Maximum [Member] | Performance Shares [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Share Based Compensation Arrangement, Possible Number Of Shares Issued Each Year 147,368,000 94,972,000  
Common Stock [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Issuance of restricted stock as deferred compensation to employees and directors 20,216    
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]      
Exercised (in shares) (42,636) (43,121) (29,056)