v2.4.0.8
Disclosure - Pro Forma Financial Information (Detail) (USD $)
In Thousands, except Per Share data, unless otherwise specified
3 Months Ended 9 Months Ended 12 Months Ended
Sep. 30, 2013
Sep. 30, 2012
Sep. 30, 2013
Sep. 30, 2012
Dec. 31, 2012
Dec. 31, 2011
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]            
Accretion of dividends on redeemable convertible preferred stock $ (4,044) $ (5,469) $ (18,391) $ (16,291) $ (21,994) $ (13,868)
Net income (loss) attributable to common shareholders 8,290 (25,959) (45,167) (67,228) (103,868) (99,148)
Net loss attributable to common shareholders per share, basic and diluted         $ (18.77) $ (18.92)
Pro Forma [Member]
           
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]            
Revenues           9,146
Net loss           (89,116)
Accretion of dividends on redeemable convertible preferred stock           (13,868)
Net income (loss) attributable to common shareholders           $ (102,984)
Net loss attributable to common shareholders per share, basic and diluted           $ (19.01)