v2.4.0.8
Shareholders Equity (Details) (USD $)
1 Months Ended 3 Months Ended 9 Months Ended 12 Months Ended 9 Months Ended 3 Months Ended 12 Months Ended 3 Months Ended 12 Months Ended 1 Months Ended
Jun. 30, 2013
Sep. 30, 2014
Jun. 30, 2014
Mar. 31, 2014
Sep. 30, 2013
Sep. 30, 2014
Sep. 30, 2013
Dec. 31, 2013
Jul. 02, 2013
Sep. 30, 2014
Coworker Stock Purchase Plan [Member]
Sep. 30, 2014
Secondary offering over-allotment [Member]
Jun. 30, 2014
Secondary offering over-allotment [Member]
Mar. 31, 2014
Secondary offering over-allotment [Member]
Dec. 31, 2013
Secondary offering over-allotment [Member]
Sep. 30, 2014
Secondary Offering [Member]
Jun. 30, 2014
Secondary Offering [Member]
Mar. 31, 2014
Secondary Offering [Member]
Dec. 31, 2013
Secondary Offering [Member]
Dec. 31, 2013
IPO Over-allotment [Member]
Jul. 31, 2013
IPO [Member]
Class of Stock [Line Items]                                        
Share-based Compensation Arrangement by Share-based Payment Award, Discount from Market Price, Purchase Date           5.00%                            
Allocated Share-based Compensation Expense   $ 3,900,000     $ 40,300,000   $ 44,300,000     $ 0.0                    
Stock Issued During Period, Shares, New Issues                                     3,487,500 23,250,000
Share Price                 $ 17.00                      
Proceeds from Issuance Initial Public Offering               424,700,000                        
Shares sold by certain selling stockholders                     0 [1],[2] 2,250,000 [1] 1,500,000 [1] 2,250,000 [1] 15,000,000 15,000,000 10,000,000 15,000,000    
Secondary-offering related expenses   300,000 500,000 400,000   1,200,000 0 600,000                        
Proceeds from shares sold by certain selling stockholders   $ 0           $ 0                        
Stockholders' Equity Note, Stock Split, Conversion Ratio 143.0299613                                      
Common shares, par value   $ 0.01       $ 0.01   $ 0.01                        
[1] Under each underwriting agreement, the selling stockholders granted the underwriters an option, exercisable for thirty days, to purchase up to the additional amount of shares noted.
[2] The option to purchase additional shares was not exercised in connection with the September 2014 secondary offering.