Consolidated Statements of Changes in Redeemable Non-controlling Interest and Stockholders' Equity (Parenthetical) - USD ($) $ in Thousands  | 
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2016  | 
Dec. 31, 2015  | 
Dec. 31, 2014  | 
|
| Statement of Stockholders' Equity [Abstract] | |||
| Stock-based compensation expense, excess tax benefits | $ 99 | $ (50) | $ 918 | 
| X | ||||||||||
- Definition Amount of increase (decrease) in additional paid in capital (APIC) resulting from a tax benefit (deficiency) associated with an share-based compensation plan other than an employee stock ownership plan (ESOP). No definition available. 
  | 
| X | ||||||||||
- References No definition available. 
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