This is my classic location control deck, which I often play in casual games with multiple players. It is light on allies, and instead relies on exploiting Idraen's ability multiple times per turn. This doesn't happen often, but when it does, it's quite enjoyable.
The deck is best paired with another deck running Dúnedain Cache and Rivendell Bow, so that Glorfindel and Idraen can contribute to combat. You do occassionally want to engage enemies (so that you can play Expert Trackers), but generally the deck is really meant to do one thing - clear locations from the board.
Nearly every card in the deck affects locations. Strider's Path is a clutch card, as you often don't have an active location during staging (either because of Asfaloth, Lórien Guide, or because there weren't any locations to travel to last turn). Thror's Map sometimes allows you to travel to a second location in one turn (thanks to Strength of Will).
Those cards that are unrelated to location control include:
Light of Valinor - a clutch card for Glorfindel
Athelas - Great multiplayer support card for Idraen
Silver Lamp - Another support card for either Idraen or Glorfindel
Spare Hood and Cloak - Another multiplayer support card for either Idraen or Glorfindel
Deep Knowledge - Excellent card draw
A Test of Will & Hasty Stroke - Excellent encounter deck control
3 side quests - I love side quests, and have a difficult time not putting them in my decks.
I run several versions of this deck, and sometimes swap out the heroes:
Bifur -> Galdor: This deck does suffer long-term from card draw, and Galdor does improve that significantly, but at the cost of foregoing the first-turn Asfaloth and the Ravenhill Scouts (which become much too expensive).
These other two are a lot more combo-heavy, and therefore aren't quite as good:
Bifur -> Grima and Glorfindel -> Theodred: Grima smooths the resource curve, and Theodred gives you access to the handful of Leadership location control cards (Snowbourne Scout, Ranger Provisions), not to mention Dúnedain Cache for Idraen, and Ranger Summons (which is one of my all-time favorite cards).
Glorfindel -> Prince Imrahil: The Prince readies much like Idraen, and can support players during combat with Dúnedain Cache in the same way that Idraen can. He's also great once he has Sentinel and a Gondorian Shield (obviously, someone else must be running a Tactics deck to give you this card).