Summary of Significant Accounting Policies (Tables)
 12 Months Ended
Dec. 31, 2016
Accounting Policies [Abstract]  
Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]
The fair value of stock options granted during the year ended December 31, 2016 was estimated using the Black-Scholes option-pricing model, based on the following weighted-average assumptions:

 
Weighted-Average Assumptions
 
 
Risk-free interest rate
1.1%
Term
3.06
Volatility
53%
Dividend yield
—%
Property and Equipment, Useful Lives
Depreciation and amortization is computed on a straight-line basis over the following estimated useful lives of the assets:
Furniture and fixtures
3 to 5 years
Computer hardware and software
3 to 5 years
Leasehold improvements
2 to 5 years (Lesser of lease term or useful life of improvement)
Schedule of Earnings Per Share, Basic and Diluted

The following table presents the weighted-average number of common shares outstanding used in the calculation of basic and diluted income per share:
 
 
2016
 
2015
 
2014
Numerator (in thousands):
 
 
 
 
 
 
Basic and Diluted
 
 
 
 
 
 
Net loss
 
$
(54,067
)
 
$
(160,036
)
 
$
(66,029
)
Total dividends declared / paid
 
—

 
(25,434
)
 
(25,039
)
Dividends attributable to common stockholders
 
—

 
24,740

 
24,313

Net loss attributable to common stockholders – basic and diluted
 
$
(54,067
)
 
$
(160,730
)
 
$
(66,755
)
 
 
 
 
 
 
 
Denominator:
 
 
 
 
 
 
Weighted-average shares used in computing net loss per share attributable to common stockholders – basic and diluted
 
50,075,847

 
49,505,817

 
48,658,088

 
 
 
 
 
 
 
Basic and diluted net loss per common share
 
$
(1.08
)
 
$
(3.25
)
 
$
(1.37
)
Anti-dilutive equity-based incentive awards excluded from the computation of diluted loss per share
 
3,682,532

 
71,468

 
27,760