Shareholders' Equity/Capital Stock - Employee Stock Purchase Plan and Executive Savings Plan (Details)	4 Months Ended	162 Months Ended
	Sep. 18, 2012	Apr. 30, 2012	Dec. 31, 1992
Employee Stock Purchase Plan [Abstract]
Minimum employment length for plan participation	90 days
Discounted stock purchase price, under the plan, as a percent of market price	85.00%
Maximum number of shares authorized		1,000,000
Number of shares comulatively purchased through the plan		169,822
Number of shares held by custodian		42,808
Executive Savings Plan, Shares in Plan [Abstract]
Maximum number of shares reserved for issuance under the plan, adjusted for capitalization			58,492
Maximum number of shares reserved for issuance under the plan			50,000
Number of shares in reserve at period end	38,553
Number of shares allocated but not issued to participants	19,722