Annual report pursuant to Section 13 and 15(d)

Stock-Based Compensation Expense - Restricted Shares (Details)

v3.4.0.3
Stock-Based Compensation Expense - Restricted Shares (Details) - USD ($)
 12 Months Ended
Mar. 31, 2016
Mar. 31, 2015
Mar. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Issuance of restricted stock as deferred compensation to employees and directors   11,956  
Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Grants In Period, Value   $ 289,000  
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]      
Exercised (in shares)     (18,786)
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)     $ 21.52
Restricted Stock [Member]      
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]      
Outstanding, beginning of period (in shares) 0 18,000 21,000
Granted (in shares) 0 0 17,000
Exercised (in shares) 0 (18,000) (21,000)
Forfeited (in shares) 0 0 0
Outstanding, end of period (in shares) 0 0 18,000
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) $ 0.00 $ 20.09 $ 18.09
Granted, weighted average exercise price (in dollars per share) 0.00 0.00 20.09
Exercised, weighted average exercise price (in dollars per share) 0.00 20.09 18.09
Forfeited, weighted average exercise price (in dollars per share) 0.00 0.00 0.00
Options outstanding, weighted average grant price, end of period (in dollars per share) $ 0.00 $ 0.00 $ 20.09
Restricted Stock Units (RSUs) [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Aggregate intrinsic value $ 3,375,000    
Total unrecognized expense related to non-vested stock option awards $ 2,630,000    
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]      
Outstanding, beginning of period (in shares) 198,822 164,325 71,109
Granted (in shares) 98,009 96,462 117,904
Exercised (in shares) (69,704) (46,623)  
Forfeited (in shares) (34,906) (15,342) (5,902)
Outstanding, end of period (in shares) 192,221 198,822 164,325
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) $ 22.38 $ 20.53 $ 21.52
Granted, weighted average exercise price (in dollars per share) 24.08 24.44 20.14
Exercised, weighted average exercise price (in dollars per share) 21.97 20.67  
Forfeited, weighted average exercise price (in dollars per share) 22.53 20.76 21.52
Options outstanding, weighted average grant price, end of period (in dollars per share) $ 23.36 $ 22.38 $ 20.53
Stock based compensation, recognition period 1 year 5 months 15 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 $ 1,113,000 $ 1,187,000 $ 480,000
Total unrecognized expense related to non-vested stock option awards $ 871,000    
Vested shares 31,658,000 19,446,000 12,254,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]      
Granted (in shares) 22,989,000 15,162,000 10,594,000
Forfeited (in shares) (8,669,000) (4,284,000) (1,660,000)
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]      
Stock based compensation, recognition period 1 year 7 months 28 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 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 76,172,000 77,406,000 24,192,000
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 18,578   17,416
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]      
Exercised (in shares) (29,056) (88,050) (566,487)