Stockholders' Equity (Details) (USD $)	1 Months Ended					3 Months Ended			6 Months Ended		12 Months Ended
	Jun. 30, 2012	May 31, 2012	Apr. 30, 2012	Mar. 31, 2012	Feb. 29, 2012	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2008	Jan. 25, 2008
Summary of changes in stockholders' equity [Roll Forward]
Balance at beginning of period									$ 249,355,000
Net Income						704,000	2,838,000		8,640,000	26,918,000
Dividend Payments									(4,805,000)
Unrealized Foreign Currency Translation Gain						(170,000)	56,000		(79,000)	74,000
Unrealized Holding Gain on Marketable Securities						37,000	(4,000)		188,000	83,000
Net Change in Fair Value of Derivatives						(1,127,000)	(590,000)		70,000	403,000
Share-based compensation expense (net of forfeited shares)									(125,000)
Balance at end of period	253,244,000					253,244,000			253,244,000
Stock Repurchase Program [Abstract]
Shares authorized for repurchase (in shares)												1,000,000
Total number of shares purchased (in shares)	0	0	0					223,051			491,572
Payments for shares purchased								5,200,000			11,500,000
Average Price Paid per Share (in dollars per share)	$ 0	$ 0	$ 0
Total Number of Shares Purchased as Part of Publicly Announced Plan (in shares)	0	0	0
Maximum Number of Shares that May Yet Be Purchased Under the Plan (in shares)	285,377	285,377	285,377			285,377			285,377
Treasury stock shares retired to meet tax liabilities				16,439	13,665
Dividend Payments [Abstract]
Record Date	May 16, 2012			Feb. 15, 2012
Payment Date	Jun. 01, 2012			Mar. 01, 2012
Per Share Amount (in dollars per share)	$ 0.250			$ 0.375
Total Dividend Paid	1,801,000			2,690,000					4,805,000	5,625,000
Total dividends paid, excluding dividends related to unvested stock awards									4,491,000
Payment of cash dividends related to unvested stock awards									$ 314,000