XML 33 R56.htm IDEA: XBRL DOCUMENT v2.4.0.6
Long-term debt - Additional Information (Detail) (USD $)
 1 Months Ended 3 Months Ended 1 Months Ended 3 Months Ended
Apr. 12, 2011
Senior Secured Notes [Member]
Jun. 30, 2011
Senior Secured Notes [Member]
Mar. 31, 2013
Senior Secured Notes [Member]
Apr. 12, 2011
Senior Secured Credit Note [Member]
Apr. 12, 2011
Subordinated Note [Member]
Mar. 31, 2013
Senior Secured Notes [Member]
Mar. 31, 2012
Senior Secured Notes [Member]
Dec. 31, 2011
Senior Secured Notes [Member]
Nov. 30, 2011
Senior Secured Notes [Member]
Debt Instrument [Line Items]                  
Issuance of private placement, Principal amount $ 200,000,000                
Interest rate 8.75%                
Retirement Of Notes, Principal amount       22,400,000 100,000,000        
Cost to issue the Notes   4,600,000              
Term of payments of interest on notes Semi-annually                
Private placement date Apr. 12, 2011                
Repurchase of notes                 5,000,000
Repurchase of notes at cost                 4,700,000
Gain on repurchase notes               300,000  
Interest expense on note           4,300,000 4,300,000    
Senior Notes Trading value     107.56            
Senior Notes base value     $ 100