XML 33 R32.htm IDEA: XBRL DOCUMENT  v2.3.0.11
Stock-Based Compensation (Narrative) (Details) (USD $)
 3 Months Ended
Jun. 30, 2011
Jun. 30, 2010
Stock options granted in period 634,000  
Restricted stock granted in period 213,000  
Performance-based restricted stock granted in period 5,000  
Shares granted vesting period, years 3  
Number of shares returned to pay withholding taxes 23,861  
Value of shares returned to pay withholding taxes $ 300,000  
Stock-based compensation expense 3,466,000 3,578,000
Minimum [Member] | U.S. Treasury rates [Member]
    
Average time period taken in calculating risk-free interest rate   5
Maximum [Member] | U.S. Treasury rates [Member]
    
Average time period taken in calculating risk-free interest rate   7
Stock Options [Member]
    
Unrecognized compensation cost for unvested employee stock-based compensation awards outstanding, net of forfeitures 12,600,000  
Period over which unrecognized compensation expense is expected to be recognized (years) 2.6  
Stock-based compensation expense 600,000  
Restricted Stock [Member]
    
Unrecognized compensation cost for unvested employee stock-based compensation awards outstanding, net of forfeitures $ 6,500,000  
Period over which unrecognized compensation expense is expected to be recognized (years) 2.3