Annual report pursuant to Section 13 and 15(d)

Summary of Significant Accounting Policies - Recent Accounting Pronouncements (Details)

v3.8.0.1
Summary of Significant Accounting Policies - Recent Accounting Pronouncements (Details) - USD ($)
$ in Thousands
Dec. 31, 2017
Jan. 01, 2017
Accounting Standards Update 2014-09    
New Accounting Pronouncements or Change in Accounting Principle [Line Items]    
Deferred income tax assets, net $ 1,700  
Accounting Standards Update 2014-09 | Retained Earnings    
New Accounting Pronouncements or Change in Accounting Principle [Line Items]    
Credit to retained earnings (4,700)  
Accounting Standards Update 2016-09    
New Accounting Pronouncements or Change in Accounting Principle [Line Items]    
Deferred income tax assets, net   $ 4,000
Accounting Standards Update 2016-09 | Retained Earnings    
New Accounting Pronouncements or Change in Accounting Principle [Line Items]    
Credit to retained earnings   $ 4,000
Gross revenues | Accounting Standards Update 2014-09    
New Accounting Pronouncements or Change in Accounting Principle [Line Items]    
Credit to retained earnings (9,100)  
Costs | Accounting Standards Update 2014-09    
New Accounting Pronouncements or Change in Accounting Principle [Line Items]    
Credit to retained earnings $ (2,700)