Employee Benefit Plans (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Jun. 30, 2012	Jun. 30, 2011
Employee Benefit Plans [Abstract]
Recorded compensation expense	$ 1,629	$ 1,229
Defined Benefit Plan Disclosure [Line Items]
Contributions by employer	2,150	5,050
Additional contributions	8,350
Pension [Member]
Pension and postretirement benefit plans [Abstract]
Service cost	141	426
Interest cost	3,341	3,505
Expected return on plan assets	(4,031)	(3,848)
Amortization of [Abstract]
Unrecognized net loss (gain)	1,255	1,996
Unrecognized prior service credit	0	0
Net periodic benefit cost (income)	706	2,079
Postretirement [Member]
Pension and postretirement benefit plans [Abstract]
Service cost	11	12
Interest cost	74	85
Expected return on plan assets	0	0
Amortization of [Abstract]
Unrecognized net loss (gain)	0	(12)
Unrecognized prior service credit	(372)	(416)
Net periodic benefit cost (income)	$ (287)	$ (331)

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The amount of gains or losses recognized in net periodic benefit cost.

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The amount of the prior service cost or credit recognized in net periodic benefit cost relating to benefit changes attributable to plan participants' prior service pursuant to a plan amendment or a plan initiation.

+ References

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- Definition

The increase in the fair value of plan assets from contributions made by the employer.

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- Definition

The employer's best estimate, as soon as it can be reasonably determined, of contributions expected to be paid to the plan in the current remaining fiscal period. Estimated contributions may be presented in the aggregate combining (1) contributions required by funding regulations or laws, (2) discretionary contributions, and (3) noncash contributions.

+ References

No definition available.

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- Definition

An amount calculated as a basis for determining the extent of delayed recognition of the effects of changes in the fair value of assets. The expected return on plan assets is determined based on the expected long-term rate of return on plan assets and the market-related value of plan assets.

+ References

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- Definition

The increase in a defined benefit pension plan's projected benefit obligation or a defined benefit postretirement plan's accumulated postretirement benefit obligation due to the passage of time.

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- Definition

The total amount of net periodic benefit cost for defined benefit plans for the period. Periodic benefit costs include the following components: service cost, interest cost, expected return on plan assets, gain (loss), prior service cost or credit, transition asset or obligation, and gain (loss) due to settlements or curtailments.

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- Definition

The actuarial present value of benefits attributed by the pension benefit formula to services rendered by employees during the period. The portion of the expected postretirement benefit obligation attributed to employee service during the period. The service cost component is a portion of the benefit obligation and is unaffected by the funded status of the plan.

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The amount of pension and other (such as medical, dental and life insurance) postretirement benefit costs recognized during the period for (1) defined benefit plans (periodic benefit costs include the following components: service cost, interest cost, expected return on plan assets, gain (loss) on assets, prior service cost or credit, transition asset or obligation, and gain (loss) due to settlements or curtailments) and for (2) defined contribution plans (to the extent that a plan's defined contributions to an individual's account are to be made for periods in which that individual renders services, the net cost for a period is the contribution called for in that period; if a plan calls for contributions for periods after an individual retires or terminates, the estimated cost is accrued during the employee's service period).

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