MongoDB won't save JSON document?

Quick question, but does anyone have a clue why MongoDB won't save the following document? I'm using MongoJS in NodeJS to connect to MongoDB and using the following lines of code to save (in my JS file, the function call is underneath the variable definition). The save function doesn't save, but automatically goes to the callback function.

Any thoughts? Thanks so much :).

Edit: After adding an error log to the callback, I'm getting the following error:

{ [MongoError: error parsing element 0 of field documents :: caused by :: wrong type for '0' field, expected object, found 0: "{"Word":"Count","read":1,"letter":1,"wh":1,"urging":2,"swift":1,"approval":1,"add'l":1,"lease":1,"space":1,"fayetteville":1,"vamc":1,"vets":2,"care":1..."]
  name: 'MongoError',
  ok: 0,
  errmsg: 'error parsing element 0 of field documents :: caused by :: wrong type for \'0\' field, expected object, found 0: "{"Word":"Count","read":1,"letter":1,"wh":1,"urging":2,"swift":1,"approval":1,"add\'l":1,"lease":1,"space":1,"fayetteville":1,"vamc":1,"vets":2,"care":1..."',
  code: 9 }

db.collection.save(json_buffer, function() {
    console.log("Complete");
});

  var json_buffer = {"Word":"Count","read":1,"letter":1,"wh":1,"urging":2,"swift":1,"approval":1,"add'l":1,"lease":1,"space":1,"fayetteville":1,"vamc":1,"vets":2,"care":1,"@gnip":3,"--":3,"delivering":3,"data":3,"happy":3,"customers":3,"outrageous":1,"france":1,"sell":1,"warships":1,"putin":1,"@senatorkirk":1,"@repkinzinger":1,"@usrepkeating":1,"&amp":5,"urge":1,"strong":1,"action":3,"polling":1,"shows":1,"race":1,"close":1,"pitch":1,"pre-primary":1,"deadline":1,"goal":2,"joining":1,"@teamcavuto":1,"shortly":1,"discuss":1,"can’t":1,"continue":1,"punt":1,"debt":2,"crisis":1,"road":1,"watch":1,"opening":1,"remarks":1,"today’s":1,"senate":1,"committee":1,"hearing":1,"mcdonald":1,"nomination":1,"urged":1,"passage":1,"#summermealsact":2,"yesterday":1,"#monticello":1,"#ny--so":1,"impt":1,"expand":1,"@usda's":1,"summer":2,"nutrition":1,"program":1,"great":2,"catch":1,"high":1,"school":2,"friend":1,"john":1,"choate":1,"today":7,"family":1,"capitol":1,"hill":1,"child":1,"america":1,"wake":1,"day":1,"wondering":1,"eat":1,"nebraska":1,"communities":1,"access":1,"local":1,"tv":1,"programming":1,"introduced":1,"bill":4,"work":2,"past":1,"time":2,"congress":1,"meaningful":1,"reduce":1,"threat":1,"cyber":1,"attacks":1,"@mercnews":1,"op-ed":1,"fitting":1,"@us_sfrc":1,"passed":1,"#crpd":1,"bob":1,"dole's":1,"bday":1,"#disabilitytreaty":1,"advocate":1,"beginning":1,"#isupportcrpd":1,"senator":1,"mcconnell":2,"co-sponsors":1,"protect":2,"correctional":1,"officers":2,"daily":1,"independent":2,"#ashland":1,"#kentucky":1,"millions":1,"children":2,"recv":1,"free":1,"reduced":1,"meals":1,"year":1,"left":1,"hungry":1,"months":1,"unacceptable":1,"rt":5,"@aterkel":1,"record":1,"phone":1,"@senschumer":1,"…":1,"good":1,"meeting":1,"anne":1,"rung":1,"nominee":1,"@ombpress":1,"office":2,"fed":1,"procurement":1,"policy":1,"cc":1,"@senatehsgac":1,"@federalreserve":1,"divert":1,"leftover":1,"funds":1,"foreclosure":1,"review":1,"hardest":1,"hit":1,"fund":1,"#ri":1,"supports":1,"corrections":1,"prisons":1,"manchester":1,"pine":1,"knot":1,"ashland":1,"inez":1,"lex":1,"miami":1,"valley":1,"well-run":1,"base":1,"makes":1,"wright-patt":1,"#1":1,"airmen":1,"@gopoversight":1,"release":1,"#irs":2,"needed":1,"days":1,"confirm":1,"lerner":1,"hard":2,"drive":1,"crash":2,"provide":1,"support":3,"runaway":1,"homeless":1,"youth":1,"victims":1,"trafficking":1,"@housefloor":1,"tomorrow":1,"glad":1,"signature":1,"industry":1,"@kydistillers":1,"@repandybarr":1,"obama":1,"meant":1,"flexibility":1,"re-elected":1,"thoughts":1,"prayers":1,"affected":1,"fires":1,"tooele":1,"pray":1,"staying":1,"safe":1,"#utpol":1,"hr":1,"passes":1,"house":1,"@repderekkilmer":1,"modernize":1,"labs":1,"fyi":1,"fun":1,"activities":1,"hosted":1,"google":1,"young":1,"inventors":1,"age":1,"13+":1,"choose":1,"projects":1,"virtual":1,"field":1,"trips":1,"joined":1,"nyc":1,"workforce":2,"development":2,"hosting":1,"roundtable":1,"#bronx":1,"failure":1,"disclose":1,"timely":1,"manner":1,"destroyed":1,"critical":1,"evidence":1,"reason":2,"special":1,"prosecutor":1,"26%":1,"texas":1,"live":1,"poverty":1,"#raisethewage":1,"#honorflightact":2,"codify":1,"process":1,"tsa":1,"expedited":1,"dignified":1,"screening":1,"veterans":1,"visiting":1,"war":1,"memorials":1,"humbled":1,"join":2,"medal":1,"honor":1,"recipient":1,"staff":1,"sergeant":1,"ryan":1,"pitts":1,"nashua":1,"ceremony":1,"pentagon":1,"icymi":1,"statement":1,"halbig":1,"burwell":1,"@ecpzachevans":1,"save":1,"date":1,"mt":1,"@shrinersfest":1,"dates":1,"announced":1,"shrinersfest":1,"june":1,"25-28":1,"feat":1,"@blueangels":1,"htt…":1,"unleash":1,"america's":1,"energy":2,"abundance":1,"create":1,"#jobs":1,"economic":1,"growth":1,"affordable":1,"#yes2energy":1,"marks":1,"#100days":1,"nigerian":1,"schoolgirls":1,"kidnapping":1,"forgotten":1,"#bringbackourgirls":1,"pleased":1,"mayor":1,"@rahmemanuel":1,"taking":1,"@fly2ohare":1,"noise":1,"measure":1,"seeks":1,"pay":1,"gratitude":1,"group":1,"americans":1,"make":1,"ultimate":1,"sacrifice":1,"stopped":1,"dutch":1,"embassy":1,"offer":1,"condolences":1,"lost":1,"loved":1,"#mh17":1,"#obamafailures":1,"min":1,"#131":1,"odds":1,"drives":1,"irs":1,"claims":1,"win":1,"fl":1,"lottery":1,"times":1,"#tcot":1}