XML 106 R52.htm IDEA: XBRL DOCUMENT v3.7.0.1
Available-for-Sale Marketable Securities - Narrative (Details)
12 Months Ended
Dec. 31, 2016
USD ($)
position
Investments, Debt and Equity Securities [Abstract]  
Number of positions in an unrealized loss position, less than 12 months 6
Number of investment positions 20
Other-than-temporary impairments | $ $ 0