Annual report pursuant to Section 13 and 15(d)

Stock Compensation Plans - Stock Option Awards (Detail)

v2.4.1.9
Stock Compensation Plans - Stock Option Awards (Detail) (USD $)
In Thousands, except Per Share data, unless otherwise specified
12 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Mar. 31, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]      
Outstanding, Shares Under Option, Beginning Balance 93us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber 146us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber 114us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber
Granted, Shares Under Option     49us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross
Exercised, Shares Under Option (2)us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised (52)us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised (13)us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised
Forfeited, Shares Under Option (1)us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod (1)us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod (4)us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod
Outstanding, Shares Under Option, Ending Balance 90us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber 93us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber 146us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber
Outstanding, Weighted Average Exercise Price, Beginning Balance $ 18.60us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice $ 16.04us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice $ 13.90us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice
Vested or expected to vest, Shares Under Option 87us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingNumber    
Granted, Weighted Average Exercise Price     $ 18.65us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice
Exercisable, Shares Under Option 76us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber    
Exercised, Weighted Average Exercise Price $ 19.66us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice $ 11.31us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice $ 6.35us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice
Forfeited, Weighted Average Exercise Price $ 18.65us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice $ 19.15us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice $ 18.65us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice
Outstanding, Weighted Average Exercise Price, Ending Balance $ 18.57us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice $ 18.60us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice $ 16.04us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice
Vested or expected to vest, Weighted Average Exercise Price $ 18.57us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageExercisePrice    
Exercisable, Weighted Average Exercise Price $ 18.56us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice    
Outstanding, Weighted Average Remaining Contractual Term, Ending Balance 5 years 3 months 22 days    
Vested or expected to vest, Weighted Average Remaining Contractual Term 5 years 2 months 27 days    
Exercisable, Weighted Average Remaining Contractual Term 4 years 11 months 19 days    
Outstanding, Aggregate Intrinsic Value, Ending Balance $ 598us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue    
Vested or expected to vest, Aggregate Intrinsic Value 582us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingAggregateIntrinsicValue    
Exercisable, Aggregate Intrinsic Value $ 524us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1